Nonlinear System Identification Using an Analog Technique

The prime purpose of this thesis project is to investigate and to implement Kohr\u27s method. Kohr\u27s method of identification was selected for study mainly because of the easy accessibility of the analog computer, in addition to the other advantages mentioned above. In this thesis the method of Kohr is shown to apply to the identification of single-valued nonlinearities. However, it is also shown in the work to follow that the method does not apply, in general, to double-valued nonlinearities. Further, an extension of this method is developed herein which enables the determination of system order. A number of examples illustrating the implementation of the method, its restriction, and extension are given in the thesis

End wall flows in rotors and stators of a single stage compressor

A computer code for solving the parabolized Navier-Stokes equations for internal flows was developed. Oscillations that develop in the calculation procedure are discussed. The measurements made in the hub and annulus wall boundary layers are summarized. The flow in the hub wall boundary layer, starting ahead of the inlet guide vanes to the inlet of the rotor is traced

The influence of magnesium and oxalic acid upon the absorption and retention of calcium and phosphorus

The present work was undertaken to study the effect of excess of magnesium and oxalic acid on calcium-phosphorus utilization, retention and excretion when added to a normal balanced ration fed to lambs

Free a-amino acid nitrogen content of the skeletal muscle of some marine fishes and invertebrates

In the course of an investigation of the nitrogenous extractives of fresh fish muscle the authors determined the a-amino acid nitrogen content of the aqueous extracts of the skeletal muscle in a number of marine fishes

Preservation of prawns in ice and the assessment of their quality by objective standards

Prawns and other crustaceans contribute about 15% of the total marine fish landings in India. Our present annual production of prawns is over 100,000 tons, ranking next only to that of the U.S.A. Large quantities of prawns are preserved by sundrying after previously boiling in salt solution for the internal market as well as for export to Ceylon, Burma and Malaya. A relatively small fraction is sent in ice to inland towns by rail or other conveyance. In recent years a considerably valuable trade in export of frozen prawns and lobsters to the U.S.A. has developed

Duality and Non-Commutative Gauge Theory

We study the generalization of S-duality to non-commutative gauge theories. For rank one theories, we obtain the leading terms of the dual theory by Legendre transforming the Lagrangian of the non-commutative theory expressed in terms of a commutative gauge field. The dual description is weakly coupled when the original theory is strongly coupled if we appropriately scale the non-commutativity parameter. However, the dual theory appears to be non-commutative in space-time when the original theory is non-commutative in space. This suggests that locality in time for non-commutative theories is an artifact of perturbation theory.Comment: 7 pages, harvmac; a typo fixe

Fishery potential of the Gulf of Kachchh

Fishery potential of the interior Gulf of Kachchh and adjacent creek regions was reported for the first time as baseline data for future ecological assessment. The experimental trawling and gill netting indicated that the inner Gulf (av. 7.8 kg/h) was three times more productive than the creek (av. 2.3 kg/h). The number of species found in the Gulf and creek were respectively 34 and 20 suggesting good biodiversity of the living resources of the area

Utility of Different Electrocardiographical Leads during Diagnostic Ajmaline Test for Suspected Brugada Syndrome

In order to compare the value of different leads and lead combinations to detect the signature Brugada type ECG pattern, we analysed digital 10-second, 15-lead ECGs (12 standard leads + leads V1 to V3 from 3rd intercostal (i.c.) space, V1h to V3h) acquired during diagnostic Ajmaline testing in 128 patients (80 men, age 37±15 years) with suspected Brugada syndrome (BS) (patient group), 15-lead resting ECGs of 108 healthy subjects (53 men, age 31.9±10.5 years) (control group A) and standard 12-lead resting ECGs of 229 healthy subjects (111 men, age 33±4 years) (control group B). Bipolar leads between V2 (positive pole) and V4 or V5 (leads V2-4V2-5) were derived by subtracting leads V4 and V5 from V2 (custom-made program). The 6 peripheral, 6 right precordial leads (V1 to V3, V1h to V3h) and leads V2-4 and V2-5 of the patients group, leads V1h to V3h of control group A, and leads V2-4 and V2-5 of control group B were analysed for the presence of type 1 Brugada pattern. There were 21 (16.4%) positive and 107 (83.6%) negative Ajmaline tests. In 7 positive tests (33%), type 1 pattern appeared only in leads V1h to V3h, whereas in 14 tests 67%) it appeared in both V1 to V3 and V1h to V3h. Lead V2 displayed type 1 pattern during 10 positive tests; in all of them, plus 10 other positive tests type 1 was also noted in lead V2h (n=20, 95.2%). In all 10 cases, in which lead V2 exhibited type 1 pattern (n=10), lead V2-4 and/or V2-5 also exhibited type 1-like pattern. During 7 positive tests, in which lead V2h but not V2 exhibited type 1 pattern, lead V2-4 and/or V2-5 also demonstrated type 1 pattern. Type 1 pattern was observed in leads V3 and V3h during 1 (5%) and 5 (24%) positive tests, in 0 ECGs (0%) in control group A and in 1 ECG (0.4%) in control group B. In conclusion, the "high" V1 and V2 leads (3rd i.c. space) detect more sensitively Brugada type 1 pattern than the standard V1 and V2 leads (4th i.c. space); leads V3 and V3h are not essential for the diagnosis of BS; bipolar leads V2-4 and V2-5 are superior to lead V2 for the ECG diagnosis of BS

Spatial synchronization and extinction of species under external forcing

We study the interplay between synchronization and extinction of a species. Using a general model we show that under a common external forcing, the species with a quadratic saturation term in the population dynamics first undergoes spatial synchronization and then extinction, thereby avoiding the rescue effect. This is because the saturation term reduces the synchronization time scale but not the extinction time scale. The effect can be observed even when the external forcing acts only on some locations provided there is a synchronizing term in the dynamics. Absence of the quadratic saturation term can help the species to avoid extinction.Comment: 4 pages, 2 figure

Multifunctional finishes on cotton textiles using combination of chitosan and polycarboxylic acids

100% cotton fabric has been treated with suitable combinations of chitosan and polycarboxylic acids (PCAs) to impart multiple functional properties. It is found that irrespective of the type of PCA added, samples treated with all combinations of chitosan and PCAs exhibit very good protection against Escherichia coli and Staphylococcus aureus bacterial strains. Zone of bacterial inhibition ranges from 21mm to 25mm and 24mm to 27mm for these strains respectively. Addition of PCAs to chitosan helps to improve other functional properties, like crease recovery behavior, soil release property and flame retardency in addition to the antimicrobial property. Samples treated with the mixture of chitosan and PCAs show good thermal resistance with Class I flammability. Maleic acid with chitosan shows higher values of flame propagation time as compared to that of other PCAs combination with chitosan. Soil release property is also improved from grade 3 for parent sample to grade 5 for all combinations of PCAs + chitosan treated samples. The crease recovery angle of samples treated with chitosan and PCAs combination has increased upto 2610 compared to 2150 for parent sample. Loss of tensile strength and tearing strength is found to be lower in chitosan and PCAs combination samples than in resin treated samples. From the results, it is evident that all the combinations of PCAs and chitosan can impart multiple functional properties on cotton materials