A Study on Optimal Transmission System Planning

In this paper, the author deals with the optimal transmission system planning based on topological considerations. The development of mathematical technique, particularly, the network flow theory has enabled the system planning taking account of topological situations. The construction cost characteristics for the actual transmission system are frequently expressed by a staircase function. The paper describes the method for solving these transmission system planning by means of integer linear programming with zero-one variables

Optimum Sampled-Data Control System Design by Dynamic Programming Technique

In this paper, the authors deal with an application of dynamic programming technique to an optimum sampled-data control system design. Since the optimum sampled-data control problem may be treated as an n-stage decision process, the determination of the optimum control law is carried out by means of the dynamic programming technique. Optimum control policies are derived to fulfill the minimum integral squared error for the deterministic case and the minimum expected value of integral squared error for the stochastic case. It is shown that the control signal of the optimum system consists of a linear combination of system variables. The over-all optimum control system is a time-varying system. However, the quasi-optimum control can be achieved by feeding back all the state variables through appropriate constant multipliers and the quasi-optimum control system can be considered as a good approximation of the optimum system

Analysis of the Characteristics of a Synchronous Generator by means of Air Gap Flux

This paper describes the analysis of the characteristics of a synchronous generator on the basis of air gap fluxes measured by a search coil on the stator tooth top. It is especially concerned with the loss of synchronism process which governs the stability of an electric power system, but has not yet been made clear physically. That is to say, the principles of measuring air gap flux by using a search coil, methods of determining direct axis positions, derivation of no-load air gap flux density distribution, derivation of armature reaction flux, and the analysis of the loss of synchronism process are described. This is a modified paper of our previous works which is aimed at giving a total understanding of the physical behavior of a synchronous generator connected to an electric power system, over the wide range of operations from the sready-state to the step-out process. This will contribute to the efforts of both the design engineers of electrical apparatus and the power system engineers

On the Iteration Method for the Optimal Transmission System Planning

The optimal transmission system design problem can be formulated by an integer linear program when the construction cost characteristics are expressed by a staircase function. In this paper, we deal with the iteration method to obtain more accurate approximate solution of integer linear program and the procedure to solve effectively the large linear program by use of a decomposition principle and a network flow theory. Two examples on this problem are presented

Cooling and Electrical Tests on a 30 KVA Superconducting Synchronous Generator

Cooling and electrical tests on a 30 KVA superconducting synchronous generator of the revolving armature type were performed. The method and results of the cooling test, and discussions about it are given in detail. Five electrical tests were carried out to determine the machine constants of a superconducting synchronous generator. These tests were i) open-circuit test, ii) three-phase short-circuit test, iii) three-phase sudden short-circuit test, iv) slip test, and v) extended slip test. From these experimental results, the values of the machine constants, for example the steady and the transient synchronous reactance, were caculated. The V-characteristic of the synchronous motor with no load was obtained by a synchronous condenser test

The effect of acute and repeated ethanol administration on monoamines and their metabolites in brain regions of rats.

Concentrations of norepinephrine (NE), dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were determined in eleven brain regions of rats following acute and repeated ethanol administration: (a) an intraperitoneal (i.p.) injection of 1, 2, 3 or 4g ethanol/kg body weight and (b) i.p. injection of 1 or 2g ethanol/kg body weight for seven consecutive days. After acute administration, the concentrations of monoamines and their metabolites appeared to be altered in all brain regions examined except substantia nigra and dorsal amygdala, with maximal variation 2 or 3h after 3g ethanol administration. After repeated administration, the alterations following injections of 2.0g/kg were more marked than the injections of 1.0g/kg. Generally, the levels of NE, DA and 5-HT were decreased while the levels of HVA, DOPAC and 5-HIAA were increased with a few exception. The most prominent findings were seen in the striatum, nucleus accumbens and locus coeruleus. These data indicate that concentrations of monoamines and their metabolites can be determined simultaneously in discrete brain regions and that monoaminergic systems in the brain respond region-specifically to ethanol treatment.&#60;/P&#62;</p

Detection of HBs antigen in routine paraffin embedded liver tissue by enzyme-labelled antibody technique

HB surface antigen (HBs Ag) was detected using the enzyme-labelled antibody technique on routinely processed liver biopsy material fixed in Bouin's fixative and embedded in paraffin. Of 85 examined specimens, 45 cases were HBs Ag positive by both the immunofluorescent test and the enzyme labelled antibody technique. The remaining 40 cases were negative by both techniques. The specificity of HBs Ag detected by the enzyme-labelled antibody technique was confirmed by the blocking test using guinea pig specific HBs antibody. The results indicate that the enzyme-labelled antibody technique may be useful for detecting HBs Ag on routine paraffin sections.</p

Circadian Rhythms of Atrioventricular Conduction Properties in Chronic Atrial Fibrillation With and Without Heart Failure

AbstractObjectives. We examined the circadian variations in atrioventricular (AV) conduction properties during atrial fibrillation (AF) by a technique based on the Lorenz plot of successive ventricular response (VR) intervals and analyzed their relations with clinical features.Background. The VR interval in chronic AF shows circadian variation, which is attenuated in patients with an increased risk of death. Although the VR interval is determined by the dynamic processes in the AV node randomly stimulated by rapid atrial activity, the circadian variations of the AV conduction properties related to this mechanism are unknown.Methods. In 48 patients with chronic AF, Lorenz plots were generated on overlapping sequential segments of 512 VR intervals in 24-h ambulatory electrocardiograms. For each scatter plot, the 1.0-s intercept of the lower envelope (LE1.0) of the plot and the degree of scatter above the envelope (root mean square difference from the envelope [scattering index]) were measured for estimating AV node refractoriness and concealed AV conduction, respectively.Results. In all patients, a significant circadian rhythm was observed for the average VR interval, LE1.0and scattering index, with an acrophase occurring at night. The mesor, amplitude and acrophase of LE1.0and the scattering index closely and independently correlated with the corresponding rhythm variables of the average VR interval (partial r20.98, 0.86 and 0.68 for LE1.0and 0.98, 0.92 and 0.92 for scattering index). The amplitudes of these measures were lower in patients with congestive heart failure (CHF) even after adjustment for the effects of age, duration of AF, medications, left atrial diameter and blood pressure (p < 0.01 for all).Conclusions. These results suggest that 1) both AV node refractoriness and the degree of concealed AV conduction during AF may show a circadian rhythm; 2) the circadian rhythms of these properties may independently contribute to the circadian variation of the VR interval; and 3) these circadian rhythms may be attenuated in patients with CHF

Different expression of Tn and sialyl-Tn antigens between normal and diseased human gastric epithelial cells.

Thomsen-Friedenreich antigen (T antigen) has been supposed to be a cancer-specific carbohydrate antigen. We have previously shown that one third of the Japanese population normally expressed T antigen in gastric surface epithelia and the other two thirds expressed fucosyl-T antigen. Their sialylation and blocked-synthesis were associated with diseased conditions. In the present study, we studied gastric surface epithelial expression of monosaccharide antigen Tn, i.e., a precursor of T antigen, and sialyl-Tn. Normal fundic and pyloric epithelia, respectively, expressed Tn supranucleally and cytoplasmically, but did not express sialyl-Tn. In the intestinal metaplasias and intestinal-type adenomas, goblet cells expressed sialyl-Tn in their vacuoles, and absorptive cells expressed Tn apically. In gastric-type adenomas, Tn, but not sialyl-Tn, was detected. Intestinal-type cancers expressed Tn and sialyl-Tn more often than the diffuse-type cancers. Five cancers did not express Tn, sialyl-Tn, or the T-related antigens. In these, four were diffuse-type cancers. We concluded that: a) normal gastric epithelial cells express Tn; b) metaplastic differentiation is associated with sialylation of Tn and c) expression of Tn and sialyl-Tn is depressed in the gastric cancers. </p