Not Quite Intuitionism

This is an investigation of M. Dummett's claim that a theory of meaning based on verification conditions should lead to the abandonment of classical logic in favor of intuitionistic logic. I especially concentrate on his suggestion that, in order to give the meaning of negations and conditionals, we should also take on board falsification conditions. Taken seriously, however, this route takes us not to intuitionistic logic, but rather to one of the Nelson logics

Recovery of manganese from oxidized ores as iron-and phosphorus-free soluble salts

There is a great demand at present for this country to develop its manganese resources. The hazards encountered because of the present international crisis make it almost impossible to import high-grade ores. Manganese is one of the most important strategic metals because it is vital to the production of steel. After the stock piles are depleted and the imports decreased, the deficit must be supplied by the domestic deposits. A great deal of research has been done to concentrate the domestic low-grade ores but new problems have always been encountered. The differences in the properties of the low-grade ores from various sections of the country require the application of a large number of different treatments. Because phosphorus is such an undesirable element in the production of iron and steel it is, therefore, necessary to eliminate it from the manganese concentrate used in this industry. Some of the larger domestic manganese deposits have a high phosphorus content. The concentrates produced from these deposits by the current methods often contained enough phosphorus to make them unsuitable for use in iron and steel production. It was believed the phosphorus could be eliminated if the ore were sulfated with sulfur dioxide in the gaseous state at elevated temperatures and the soluble manganous sulfate extracted with water. The presence of iron in the manganese concentrate is undesirable only because it presents a problem of corrosion in the evaporation of the leaching solution to recover the manganese. By sulfating the ore at temperatures above that at which ferrous and ferric sulfates decompose to give the water-insoluble oxides, no iron should be extracted in the leaching of the sulfated ore with water --Introduction, page 1-2

Numerical Integration Through Concavity Analysis

We introduce a relationship between the concavity of a C2 func- tion and the area bounded by its graph and secant line. We utilize this relationship to develop a method of numerical integration. We then bound the error of the approximation, and compare to known methods, finding an improvement in error bound over methods of comparable computational complexity

Independent Orbiter Assessment (IOA): Analysis of the DPS subsystem

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis/Critical Items List (FMEA/CIL) is presented. The IOA approach features a top-down analysis of the hardware to independently determine failure modes, criticality, and potential critical items. The independent analysis results corresponding to the Orbiter Data Processing System (DPS) hardware are documented. The DPS hardware is required for performing critical functions of data acquisition, data manipulation, data display, and data transfer throughout the Orbiter. Specifically, the DPS hardware consists of the following components: Multiplexer/Demultiplexer (MDM); General Purpose Computer (GPC); Multifunction CRT Display System (MCDS); Data Buses and Data Bus Couplers (DBC); Data Bus Isolation Amplifiers (DBIA); Mass Memory Unit (MMU); and Engine Interface Unit (EIU). The IOA analysis process utilized available DPS hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Due to the extensive redundancy built into the DPS the number of critical items are few. Those identified resulted from premature operation and erroneous output of the GPCs

Hyperbolic Discounting and Secondary Markets

We study the effect of hyperbolic discounting on competitive equilibria in secondary markets for a durable good. Under exponential discounting, secondary markets are irrelevant in our model. They do not affect the price in the initial period and are neutral to the allocation. Under hyperbolic discounting, secondary markets are not neutral: they do affect price and allocation. The price in the unique competitive Markov equilibrium is lower than the price in the absence of secondary markets. This affects the equilibrium supply of the durable good in the initial period. We characterise all stationary competitive equilibria in terms of prices. In particular, we obtain that there are stationary competitive equilibria in which trade occurs in each period and the allocation of the durable good is inefficient. Furthermore, we show that there exist competitive equilibria with increasing, decreasing, and cycling price paths, despite the stationarity of the market environment.hyperbolic discounting, secondary markets, durable good, time inconsistency

Independent Orbiter Assessment (IOA): Analysis of the guidance, navigation, and control subsystem

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) is presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results corresponding to the Orbiter Guidance, Navigation, and Control (GNC) Subsystem hardware are documented. The function of the GNC hardware is to respond to guidance, navigation, and control software commands to effect vehicle control and to provide sensor and controller data to GNC software. Some of the GNC hardware for which failure modes analysis was performed includes: hand controllers; Rudder Pedal Transducer Assembly (RPTA); Speed Brake Thrust Controller (SBTC); Inertial Measurement Unit (IMU); Star Tracker (ST); Crew Optical Alignment Site (COAS); Air Data Transducer Assembly (ADTA); Rate Gyro Assemblies; Accelerometer Assembly (AA); Aerosurface Servo Amplifier (ASA); and Ascent Thrust Vector Control (ATVC). The IOA analysis process utilized available GNC hardware drawings, workbooks, specifications, schematics, and systems briefs for defining hardware assemblies, components, and circuits. Each hardware item was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode