Numerical analysis of waveguide bandpass filters using singular integral equations and construction of simple design formulas

A powerful numerical solution is presented for bandpass filters in rectangular waveguides. The filters are composed of cascading of perfectly conducting inductive obstacles with zero thickness: asymmetrical windows, symmetrical windows, or symmetrical strips. The problem is reduced to a set of singular integral equations, which is solved by an extension of Lewin's quasi‐static procedure. After the accuracy of the classical formulas for the equivalent reactance is investigated, the simple inverse formulas are constructed to yield proper window widths for desired equivalent parameters. Their effectiveness is demonstrated by designing practical filters having maximally flat or equal‐ripple characteristics. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 148(4): 17–25, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10251     

Experimental studies of bistatic scattering from two-dimensionalconducting random rough surfaces

Despite the recent development of analytical and numerical techniques for problems of scattering from two-dimensional rough surfaces, very few experimental studies were available for verification. The authors present the results of millimeter-wave experiments on scattering from two-dimensional conducting random rough surfaces with Gaussian surface roughness statistics. Machine-fabricated rough surfaces with controlled roughness statistics were examined. Special attention was paid to surfaces with large rms slopes (ranging from 0.35 to 1.00) for which enhanced backscattering is expected to take place. Experimentally, such enhancement was indeed observed in both the copolarized and cross-polarized returns. In addition, it was noticed that at moderate angles of incidence, the scattering profile as a function of observation angle is fairly independent of the incident polarization and operating frequency. This independence justifies the use of the geometric optics approximation embodied in the Kirchhoff formulation for surfaces with large surface radius of curvature. When compared with the experimental data, this analytical technique demonstrates good agreement with the experimental data     

Automatic Segment Assembly Robot for Shield Tunneling Machine

Abstract: Tunnels are formed with the aid of precast reinforced-concrete segments. Erecting and positioning such segments using conventional erectors is tough and hazardous work. Labor-saving automation has long been awaited. Our development of an automatic segment assembly robot that manipulates approximately 5-ton weight segments to form a 9.5-m-diameter ring should help the situation. The robot has already found use in a 600-m-long tunnel construction site in Tokyo. High-precision assembly is achieved thanks to a light-section method that applies laser-slit lighting and to digital servo technology. The benefit of automation tied in with a manual-remote hybrid control system reduces assembly time.     

Three-Dimensional Nonlinear Dynamic Analysis of Complex High-Rise Building Structures

Abstract: Recently, designs of high-rise buildings have become more complex. Various types of buildings result, such as buildings with a semicircular plan, and buildings in which the upper floors are larger than the lower floors.
The authors have developed a three-dimensional (3-D) dynamic analysis system, 'Super DYNAMICS', which considers the nonlinear behavior of each structural member in order to analyze the structural behavior of such complex steel buildings under severe earthquakes.
This system is mainly operated on a supercomputer because of the large number of calculations required for the member level dynamic analysis.
This paper first describes the general concepts of the system and the 3-D dynamic response analysis methods, based on the nonlinear behavior of each member under axial force and biaxial bending moments, and then examines and demonstrates the precision of the yield surface of steel members created by multispring models, and the ability of the system to trace the behavior of members and frames after yielding. It shows, in addition, actual examples of a static and a dynamic analysis by three-direction ground motion applied to a 19-story steel-framed office building.     

Heat capacities of NpN and AmN

The heat capacities of NpN and AmN were determined with the drop calorimetry method. The NpN and AmN samples were prepared by the carbothermic reduction of the respective dioxides. The heat capacity of NpN obtained was in good agreement with the reported values in the temperature range from 334 to 1067 K, which was close to those of UN and PuN. The heat capacity of AmN was obtained experimentally for the first time, which was slightly smaller than those of UN, NpN and PuN in the temperature range from 354 to 1071 K.     

Establishment of a modified rankine method for the separate determination of free and combined sulphites in foods. III

Summary Considerable improvements were made to the original Rankine method. Replacement of aspiration with an injection system contributed a great deal to the simplification of procedure, being accompanied with an increase in reproducibility. Air (flow rate 1.01/min) was used for injection because the use of inert gas gave little increase in recovery rate.Sodium bisulphite (free sulphite) and three kinds of combined sulphite compound (bisulphite adducts of acetaldehyde, pyruvic acid and D-mannose) were used to find the most suitable conditions for the separate determination of free and combine sulphites.Free sulphite was expelled from the sample by bubbling at 0 °C for 30 min. It was confirmed that no combined sulphite was dissociated under these conditions. The phosphoric acid concentration had an important role in the liberation of sulphite. When 25% phosphoric acid was used, more than 99% of free sulphite was expelled by cold bubbling and more than 99% of combined sulphite was recovered by heating afterwards for 10 min.The scope of the modified Rankine method was also extended to the determination of sulphite in concentrated orange juice.

---

Verwendung der modifizierten Rankine-Methode zur getrennten Bestimmung von Sulfiten in Lebensmitteln. III

Zusammenfassung Die Rankine-Methode wurde bedeutend verbessert. Ein Umtausch der Aspiration mit Blasensystem trug beträchtlich zur Vereinfachung des Bestimmungsverfahrens bei, und die Reproduzierbarkeit wurde verbessert. Luft (Fließrate 1,01/min) wurde als Blasengas benutzt, da der Gebrauch von Inertgas für die Wiederfindungsrate unbedeutend ist.Natriumhydrogensulfit (freies Sulfit) und drei Arten gebundener Sulfite (Acetaldehydhydrogensulfit, Pyruvathydrogensulfit undd-Mannosehydrogensulfit) dienten dazu, die geeignetsten Bedingungen für die getrennte Bestimmung der freien und gebundenen Sulfite zu ermitteln.Freies Sulfit wurde bei 0 °C durch 30 min Durchblasen vertrieben. Hierbei ging kein gebundenes Sulîit verloren. Die Phosphorsäurekonzentration war wichtig für die Freisetzung des Sulfites. Wenn man 25%ige Phosphorsäure verwendet, werden > 99% freien Sulfites beim Durchblasen in der Kälte vertrieben, während > 99% gebundenen Sulfites durch nachheriges 10 min langes Erhitzen wiedergewonnen werden.Die modifizierte Rankine-Methode wurde weiterhin für konzentrierte Säfte verwendet.

---

---

Studies on the Analyses of Sulphites in Foods (III)     

Effects of ketamine-nitrous oxide anesthesia and surgical procedure serum levels of thyroxine and triiodothyronine]

503 samplings of palmitic acid in amniotic fluid are correlated with gestational age during labor or not. In nine cases of R.D.S. determinations during labor were of very low values, but not in those before labor started. Results are discussed, indicating that values over 2 mg./100 ml. show adequate pulmonary maturity. Inferior values would only be valuable if samples are obtained during labor.     

Diimide reduction of cis-1,4-polyisoprene with p-toluenesulphonylhydrazide

The hydrogenation of cis-1,4-polyisoprene with diimide generated in situ from p-toluenesulphonylhydrazide (TSH), was investigated under various conditions. In aromatic solvents at 100–140°C, the rate of hydrogenation was increased with increase in concentration of polyisoprene and of TSH. Part of the polymer was depolymerized and cyclized during the reaction. Increasing the hydrogenation tended to decrease the rate of sulphur vulcanization, of the compounded rubber and the physical properties of vulcanizates were poor. The reaction of polyisoprene rubber with TSH, was also carried out in a solid state at 140°C for 20–60 min. It was found that by using a large amount of TSH hydrogenation and cyclization of rubber occurred. The quantity of TSH used as a blowing agent, for rubber in the manufacture of sponge rubber, i.e. 5–10 phr, did not cause hydrogenation.