Studies on citrate metabolism in liver injuries. 2. Response of liver citrate to glucose load.

The effect of glucose load on the levels of blood glucose, serum non-esterified fatty acids (NEFA) and liver citrate was investigated in carbontetrachloride-intoxicated (injured) rats and compared with non-intoxicated controls. The citrate level in the liver from injured animals showed 15-fold of the value of the control. Glucose load on these animals caused gradual decrease in the citrate level, whereas similar administration to the control caused inverse results. The serum NEFA levels were lowered by glucose load in both of injured and control animals. The pattern of changes in the citrate level after glucose load in the liver from injured animals was similar to that in the muscle from the control, suggesting a similarity on citrate metabolism between the injured liver and the muscle.The possible mechanisms for these results were discussed in relation to the difference in citrate metabolism between the liver and the muscle.</p

Simulation Based Evaluation of Integrated Adaptive Control and Flight Planning Technologies

The objective of this work is to leverage NASA resources to enable effective evaluation of resilient aircraft technologies through simulation. This includes examining strengths and weaknesses of adaptive controllers, emergency flight planning algorithms, and flight envelope determination algorithms both individually and as an integrated package

Flight Test Results from the NF-15B Intelligent Flight Control System (IFCS) Project with Adaptation to a Simulated Stabilator Failure

Adaptive flight control systems have the potential to be more resilient to extreme changes in airplane behavior. Extreme changes could be a result of a system failure or of damage to the airplane. A direct adaptive neural-network-based flight control system was developed for the National Aeronautics and Space Administration NF-15B Intelligent Flight Control System airplane and subjected to an inflight simulation of a failed (frozen) (unmovable) stabilator. Formation flight handling qualities evaluations were performed with and without neural network adaptation. The results of these flight tests are presented. Comparison with simulation predictions and analysis of the performance of the adaptation system are discussed. The performance of the adaptation system is assessed in terms of its ability to decouple the roll and pitch response and reestablish good onboard model tracking. Flight evaluation with the simulated stabilator failure and adaptation engaged showed that there was generally improvement in the pitch response; however, a tendency for roll pilot-induced oscillation was experienced. A detailed discussion of the cause of the mixed results is presented

Artificial Immune System Approach for Airborne Vehicle Maneuvering

A method and system for control of a first aircraft relative to a second aircraft. A desired location and desired orientation are estimated for the first aircraft, relative to the second aircraft, at a subsequent time, t=t2, subsequent to the present time, t=t1, where the second aircraft continues its present velocity during a subsequent time interval, t1.ltoreq.t.ltoreq.t2, or takes evasive action. Action command sequences are examined, and an optimal sequence is chosen to bring the first aircraft to the desired location and desired orientation relative to the second aircraft at time t=t2. The method applies to control of combat aircraft and/or of aircraft in a congested airspace

Studies on citrate metabolism in liver injuries. 1. Fasting blood citrate level in chronic hepatitis and liver cirrhosis.

For the purpose to study the citrate metabolism in liver diseases, blood citrate, blood glucose and serum non-esterified fatty acids (NEFA) in fasting state were measured in the subjects with chronic hepatitis and with liver cirrhosis. Citrate and glucose were measured by the enzymatic methods. NEFA was measured colorimetrically. Fasting blood citrate level was investigated in relation to the type and extent of these liver diseases.Results revealed the following: 1. Fasting blood citrate level rose with the severity of liver diseases, especially in decompensated liver cirrhosis. 2. No significant difference in fasting blood citrate level was found between the subjects with and without glucose intolerance. 3. Fasting blood citrate level had a closer correlation with serum NEFA level than with blood glucose level. From these results, it has been concluded that the increase in blood citrate level in liver diseases is due to the impaired uptake of citrate by the liver and the increased release of citrate from peripheral tissues.</p

Efficient modelling of 3-d finite element mesh formation with use of 3-d topographic survey

In this decade, 3-dimensional topographic survey has been developed by using the UAV as like drones. With the technique, the complete topographies of the geo-structures can be measured. Although the accurate shapes of the geo-structures can be obtained, the numerical methods as like the finite element method is are not related to the 3-dimensional survey directly. In this research, the finite mesh modelling technique with use of the 3-D topographic survey is developed. The models of the earth-fill embankments formed from measured 3-D data are introduced as the examples

Projection Operator: A Step Towards Certification of Adaptive Controllers

One of the major barriers to wider use of adaptive controllers in commercial aviation is the lack of appropriate certification procedures. In order to be certified by the Federal Aviation Administration (FAA), an aircraft controller is expected to meet a set of guidelines on functionality and reliability while not negatively impacting other systems or safety of aircraft operations. Due to their inherent time-variant and non-linear behavior, adaptive controllers cannot be certified via the metrics used for linear conventional controllers, such as gain and phase margin. Projection Operator is a robustness augmentation technique that bounds the output of a non-linear adaptive controller while conforming to the Lyapunov stability rules. It can also be used to limit the control authority of the adaptive component so that the said control authority can be arbitrarily close to that of a linear controller. In this paper we will present the results of applying the Projection Operator to a Model-Reference Adaptive Controller (MRAC), varying the amount of control authority, and comparing controller s performance and stability characteristics with those of a linear controller. We will also show how adjusting Projection Operator parameters can make it easier for the controller to satisfy the certification guidelines by enabling a tradeoff between controller s performance and robustness

Dynamics and Adaptive Control for Stability Recovery of Damaged Aircraft

This paper presents a recent study of a damaged generic transport model as part of a NASA research project to investigate adaptive control methods for stability recovery of damaged aircraft operating in off-nominal flight conditions under damage and or failures. Aerodynamic modeling of damage effects is performed using an aerodynamic code to assess changes in the stability and control derivatives of a generic transport aircraft. Certain types of damage such as damage to one of the wings or horizontal stabilizers can cause the aircraft to become asymmetric, thus resulting in a coupling between the longitudinal and lateral motions. Flight dynamics for a general asymmetric aircraft is derived to account for changes in the center of gravity that can compromise the stability of the damaged aircraft. An iterative trim analysis for the translational motion is developed to refine the trim procedure by accounting for the effects of the control surface deflection. A hybrid direct-indirect neural network, adaptive flight control is proposed as an adaptive law for stabilizing the rotational motion of the damaged aircraft. The indirect adaptation is designed to estimate the plant dynamics of the damaged aircraft in conjunction with the direct adaptation that computes the control augmentation. Two approaches are presented 1) an adaptive law derived from the Lyapunov stability theory to ensure that the signals are bounded, and 2) a recursive least-square method for parameter identification. A hardware-in-the-loop simulation is conducted and demonstrates the effectiveness of the direct neural network adaptive flight control in the stability recovery of the damaged aircraft. A preliminary simulation of the hybrid adaptive flight control has been performed and initial data have shown the effectiveness of the proposed hybrid approach. Future work will include further investigations and high-fidelity simulations of the proposed hybrid adaptive Bight control approach