An Approach to the Analysis of Performance of Quasi-Optimum Digital Phase-Locked Loops

An approach to the analysis of performance of quasioptimum digital phase-locked loops (DPLL's) is presented. An expression for the characteristic function of the prior error in the state estimate is derived, and from this expression an infinite dimensional equation for the prior error variance is obtained. The prior errorvariance equation is a function of the communication system model and the DPLL gain and is independent of the method used to derive the DPLL gain. Two approximations are discussed for reducing the prior error-variance equation to finite dimension. The effectiveness of one approximation in analyzing DPLL performance is studied.     

Developments in marine refrigeration

The expansion in the traffic of refrigerated cargo, coupled with economic pressures, has led to developments in refrigerated cargo vessels. Containerization is rapidly replacing conventional ships. The ventilation and insulation of container ships is discussed in this paper and the design of air ducts and of temperature control systems is described, as are developments in the use of pallets for packing.Changing conditions in the fishing industry have led to an increase in vessels which freeze and store fish at sea, and these freezing systems are discussed.No references are given in the paper, but a bibliography is listed at the end.     

Measurement of Young’s modulus on small samples of amorphous metals using the impulse induced resonance technique

An impulse induced resonance technique capable of measuring the velocity of an ultrasonic extensional wave on a short (∼1 cm long) ribbonlike sample has been applied for the first time to the study of glassy metals; the Young’s modulusE was calculated from this velocity and the density. This technique is especially useful for measuringE on amorphous metal samples produced by the piston and anvil technique for rapid liquid quenching; standard techniques for measuringE are not readily applicable to such samples because of their small size. Details of the technique are given, and the dimensional limits necessary to avoid dispersion effects are discussed. The results agree well with those obtained by “pulse-echo” measurements on long ribbons. The Young’s moduli of two metallic glasses most readily prepared with the piston and anvil quenching technique are reported. L. T. KABACOFF, formerly Research Associate, Materials Science Division, Institute of Chemical Analysis, Applications and Forensic Science, Northeastern University, Boston, MA 02115. D. E. POLK, formerly Senior Scientist, Materials Science Division, Institute of Chemical Analysis, Applications and Forensic Science, Northeastern University, Boston, MA 02115     

THE INFLUENCE OF TEMPERATURE ON SOME PROPERTIES OF YEAST

The effects of temperature on the growth of yeast and on its metabolic activity in distiller's malt wort have been studied. In un-aerated fermentations, maximum yeast production takes place at about 30° C. whereas the growth rate in aerated cultures is highest at 35° C. The lag phase of the yeast studied fell from 6 hr. at 20° C. to 2·8 hr. at 25° C. and was not thereafter greatly affected by increases of temperature until 42° C. was reached, at which point growth ceased. Maltase activity was maximal at 25° C. when considered in terms of unit quantities of either yeast or fermenting wort, but the optimum temperature for initial fermentation velocity varied according to the time over which the measurement was made, being maximal at 40° C. for 0·5 hr., and at 35° C. for 2 hr. Alcohol production was highest at 25° C. whereas glycerol and higher alcohol formation took place optimally at 30° C.     

Perinatal transmitted acute icteric hepatitis B in infants born to hepatitis B surface antigen-positive and anti-hepatitis Be-positive carrier mothers

Three infants born to mothers who were hepatitis B surface antigen (HBsAg) positive and had antibody to hepatitis Be antigen (anti-HBe), developed acute icteric hepatitis B within three months of birth. All three infants clinically recovered and developed circulating anti-HBs. Contrary to previous studies, these three cases indicate that mother-infant transmission of the hepatitis B virus (HBV) does occur in infants born to HBsAg-positive, HBe-Ag-negative carrier mothers, and these infants may develop severe acute icteric hepatitis. Therefore, immunoprophylaxis in such newborns may be indicated.     

Malignant glaucoma induced by miotics postoperatively in open-angle glaucoma

A case of malignant glaucoma that developed in a patient with primary open-angle glaucoma is described. The malignant course was induced during the immediate postoperative period by the inadvertent use of miotics. The malignant course was successfully managed by osmotic agents, acetazolamide, cycloplegics, mydriatics, and topical steroids.     

Correlation of autopsy data and materials involved in the Tennessee jail fire

During 1977, a number of major fires, resulting in multiple fatalities, have caused an enhanced concern about toxic gases that are generated from synthetic materials involved in the fire. One of these fires, the Maury County, Tennessee, jail fire, was unique in that the cell padding was the only material involved in the fire. Various officials from the State of Tennessee provided material samples for polymer identification and biological samples from victims for toxicological evaluation. The results of these measurements are presented. A correlation of the toxicological findings with the material involved in the fire is presented.     

Calorimetric study of flammable fabrics. II. Analysis of flame retardant-treated cotton

Efficiencies of three flame retardants for cellulose, phosphoric acid, diammonium phosphate, and THPOH ammonia finish, have been evaluated based on the heat release value and the rate of heat release of treated fabrics burning in air measured with the isoperibol calorimeter. The results were compared and correlated with those obtained previously with the bomb-calorimetric technique. Complete heat balances were obtained for the systems studied by correlation of the calorimetric data and the measurement of combustible gases evolved from the fabric burning in air. The rate of heat release was found to correlate with the flame propagation rate measured at a 45° angle. The results from the heat, rate, and combustible gas measurements were interpretable in terms of existing mechanisms of flame-retardant action.