Finite spectrum assignment problem for systems with delay in state variables

This correspondence is concerned with the finite spectrum assignment problem for linear systems with delay in state variables. A systematic procedure for constructing the feedback law is presented on the basis of advanced elementary row operations on matrices with two variablessandz = e^{-sh}.     

Sludge depositions in a long tube-high flow MSF test plant

During the operation of a multistage flash (MSF) evaporation plant, a rather rapid decrease was observed in the economy ratio of the plant when the dissolved oxygen (DO) content of the circulating brine was at a high level. This phenomenon was brought about by the reduction of heat transfer coefficients of condenser tubes due to sludge formation on the inside tube surface by the co-precipitation of ferric hydrous oxide with silica, alumina, and organic materials. The chemical analysis of the sludge and circulating brine showed a close relationship to DO values in the brine, the concentration of iron in the sludge, and the decreasing value of the heat transfer coefficient. The lowering of DO was found very effective for avoiding the sludge trouble.     

Periodic control of continuous stirred tank reactors—III: Case of multistage reactors

The optimal periodic control of a multistage CSTR in which a nonisothermal parallel reaction is taking place is investigated. By applying the infinite-frequency pi criterion it is examined in what condition the optimal periodic control is proper. Then, the optimal steady control and the suboptimal periodic control are determined by numerical calculation. The results indicate that the improvement in the reactor performance for the periodic control relative to that for the steady control is very much increased with increase in the number of stages.     

Antihyaluronidase level in children with rheumatic fever and other streptococcal infection

1) The serum ASO and AH assays were performed and compared in a series of 90 healthy children and 7 pediatric patients with rheumatic fever and other disorders related to hemolytic streptococcus infection. 2) The upper physiological limit of serum AH titer was estimated to be 256X for children. 3) In rheumatic fever, sometimes the serum AH level rises earlier than elevation of serum ASO and remains to be high over a long period even after the serum ASO has returned to normal level. 4) The results suggest importance of the serum AH determination in the serologic diagnosis of rheumatic fever and other conditions of hemolytic streptococcus infection.     

Effect of fluid motion on radiation-induced polymerization of ethylene in a tubular reactor

The influence of the turbulence of reactant on the radiation-induced polymerization of ethylene in 40 mole-% Freon-114 (C₂Cl₂F₄) was studied using a tubular reactor at 400 kg/cm² and 25°C with a dose rate of 1.3 × 10⁵ rad/hr. At constant linear velocity and tube diameter, the polymer concentration was shown to increase linearly with the reactor tube length. This indicates that the polymerization is in a stationary state. By changing the linear velocity from 3.5 to 42.7 cm/sec and the tube diameter from 5 to 14 mm, the space time yield and the molecular weight of polymer were found to vary between 0.21 and 0.46 mole ethylene/1.-hr and from 5.0×10³ to 10.5×10³, respectively. The space time yield and molecular weight decreased sharply to about one half those in the static polymerization with increasing fluid turbulence and then slowly increased in the highly turbulent state. Similar effects were observed in a tank reactor when the stirring speed was changed.     

Diabetes mellitus and lipid metabolism (author''s transl)

Fifteen infants with pneumonia caused by respiratory syncytial virus (RSV) and 19 infants with bronchiolitis caused by RSV were studied for the influence of homologous, circulating neutralizing antibody on the severity of their illness. All infants were under nine months of age. Although maternal neutralizing antibody did not prevent infection with RSV and illness, the severity of pneumonia caused by RSV was inversely related to the level of neutralizing antibody. The severity of bronchiolitis caused by RSV was unrelated to maternal antibody levels. Chest roentgenograms showed pneumonia to be slightly more severe than bronchiolitis. Neither the severity of illness nor the presence of maternal neutralizing antibody was related to the development of complement-fixing antibody.     

The reaction of carboxylic acids with vinylmagnesium chloride

The reaction of vinylmagnesium chloride with an aromatic carboxylic acid gives a vinyl ketone. From benzoic acid, 5-oxo-5-phenyl-1-pentene is obtained. Similarly, from aliphatic carboxylic acid, a mixture of vinyl ketone and divinyl carbinol is obtained. From pentanoic acid, a mixture of butyl divinyl carbinol and 5-oxo-1-nonene is obtained.     

Activity of drimane antifeedants and related compounds against aphids,and comparative biological effects and chemical reactivity of (−)- and (+)-polygodial

A series of natural drimanes and related synthetic compounds was tested for antifeedant activity against aphids. Polygodial and warburganal were the most active. The synthetic compounds methyl 9-hydroxydrimenoate and 9-hydroxydrimenal, although active against lepidopteran larvae, were inactive against aphids. Natural (–)-polygodial and the synthetic (+) isomer showed similar levels of activity as aphid antifeedants and in phytotoxicity, fish toxicity, and human taste tests, but reacted at different rates with enantiomers of 1-phenylethylamine.