Voltage controlled oscillator is easily aligned, has low phase noise

Voltage Controlled Oscillator /VCO/, represented by an equivalent RF circuit, is easily adjusted for optimum performance by varying the circuit parameter. It contains a crystal drive level which is also easily adjusted to obtain minimum phase noise

Maser cavity servo-tuning system

Two collocated, weakly coupled probes, one loop and one dipole, detect the magnetic and electric fields inside a maser cavity. Signals from the probes are compared in phase, and the signal output from the phase detector is applied to a varactor, the reactance of which is coupled into the cavity by a microwave coupler. Alternatively, the varactor may be placed inside the cavity. Any deviation of phase from 90 deg as detected by the phase detector will then produce an error signal that will change the reactance coupled into the resonant cavity to change its reactance, and thus correct its resonance frequency. An alternative to using two probes is to use a single disk probe oriented to detect both the magnetic and electric fields, and thus provide the error signal directly

New auto-tuning technique for the hydrogen maser

Auto-tuning of the maser cavity compensates for cavity pulling effect, and other sources of contribution to the long term frequency drift. Schemes previously proposed for the maser cavity auto-tuning can have adverse effects on the performance of the maser. A new scheme is proposed based on the phase relationship between the electric and the magnetic fields inside the cavity. This technique has the desired feature of auto-tuning the cavity with a very high sensitivity and without disturbing the maser performance. Some approaches for the implementation of this scheme and possible areas of difficulty are examined

Ultra stable frequency distribution system

A system is presented for synchronizing a signal at a remotely located slave station with the phase and frequency of a signal generated at a master station. The signal transmitted at the master station and received by the slave station provides compensation for the phase shift caused by the transmission path delays between the master and slave station. The slave station transmits a signal to the master station at a frequency that is different from the frequency of the signal being transmitted by the master station. The signal transmitted by the slave station is received by the master station while the master station transmitter is off. The signal transmitted by the master station is received by the slave station while the slave station transmitter is off

Evaluation of modern hydrogen masers

The masers were tested for environmental sensitivities (magnetic field, temperature, barometric pressure) and long-term aging. Allan variance runs of 72 days were made in order to attain averaging times from several seconds to 1 million seconds. Auto- and cross-correlation techniques were used to determine the effects of uncontrolled parameters such as humidity. Three-cornered-hat and other data reduction techniques were used to determine the characteristics of the individual masers

Stabilized fiber-optic frequency distribution system

A technique for stabilizing reference frequencies transmitted over fiber-optic cable in a frequency distribution system is discussed. The distribution system utilizes fiber-optic cable as the transmission medium to distribute precise reference signals from a frequency standard to remote users. The stability goal of the distribution system is to transmit a 100-MHz signal over a 22-km fiber-optic cable and maintain a stability of 1 part in 10(17) for 1000-second averaging times. Active stabilization of the link is required to reduce phase variations produced by environmental effects, and is achieved by transmitting the reference signal from the frequency standard to the remote unit and then reflecting back to the reference unit over the same optical fiber. By comparing the phase of the transmitted and reflected signals at the reference unit, phase variations of the remote signal can be measured. An error voltage derived from the phase difference between the two signals is used to add correction phase

Ornamental plants, 1979: a summary of research

An analysis of production costs for containerized nursery products / David E. Hahn, Jerry L. Robertson, and Elton M. Smith -- Monoterpene investigations with creeping juniper cultivars (Juniperus horizontalis Moench.) / Thomas A. Fretz -- Woody flora in Hokkaido adaptable to the north central United States / Makoto Kawase -- An evaluation of microfoam on plant quality following overwintering of container-grown woody ornamentals / Christopher F. Rizzo, Elton M. Smith, and Thomas A. Fretz -- Evaluation of winter barrels as a heat source in woody ornamental winter storage structures / Christopher F. Rizzo, Elton M. Smith, and Thomas A. Fretz_ -- Effective utilization of applied fertilizer in relation to multiple flushes of growth on 'Helleri' holly / C. H. Gilliam and R. D. Wright -- Tissue nitrogen changes during a growth flush on 'Helleri' holly / C. H. Gilliam and R. D. Wright -- Controlling winter annual and perennial weeds in field-grown Cotoneaster divaricata / Elton M. Smith and Sharon A. Treaster -- Evaluation of oxadiazon for weed control in container-grown nursery stock / Thomas A. Fretz and Wendy J. Sheppard -- A 10-year evaluation of flowering crabapple susceptibility to apple scab in Ohio / Elton M. Smith -- Fungicides for the control of diseases of ornamental plants: results of 1977 trials / C. C. Powell and James A. Chatfield -- An evaluation of fungicides on container-grown woody ornamentals during winter storage under microfoam / Christopher F. Rizzo, Elton M. Smith, and Thomas A. Fretz -- Resistance of maple cultivars and species to verticillium wilt: a preliminary report / H. A. J. Hoitink, T. D. Sydnor, and C. L. Wilso

ACTH-Bestimmungen im Plasma aus dem Bulbus cranialis venae jugularis

Der Anstieg der Corticosteroninkretion in das Nebennierenvenenblut frisch hypophysektomierter Ratten diente zur Bestimmung von ACTH-Spiegeln in 1 ml nativen, menschlichen Plasma. Normale ACTH-Plasmaspiegel sind sowohl bei Punktion der Vena cubitalis als auch des Bulbus cranialis venae jugularis durch diese Methode nicht oder nur ungenau zu erfassen. Bei Patienten mit pathologisch erhöhten ACTH-Spiegeln in der Vena cubitalis sind die ACTH-Spiegel im Bulbus cranialis venae jugularis signifikant höher. Es ließ sich eine Beziehung zwischen ACTH-Spiegel in der Peripherie (Vena cubitalis), Differenz der ACTH-Spiegel zwischen Bulbus cranialis venae jugularis und Vena cubitalis und biologischer Halbwertszeit von endogenem ACTH aufstellen. Nach den Ergebnissen der Bestimmung von ACTH-Spiegeln bei Nebennierengesunden läßt sich folgern, daß die biologische Halbwertszeit von endogenem ACTH größer als 4 min sein muß. Bei Patienten mit erhöhten ACTH-Spiegeln ließ sich die biologische Halbwertszeit von endogenem ACTH größenordnungsmäßig mit ca. 40 min berechnen. Bei diesen Patienten betrug die mittlere tägliche ACTH-Inkretion ca. 100 E.ACTH-contents of 1 ml specimens of human plasma were assayed by measurement of increases of corticosterone output in the adrenal vein of acutely hypophysectomized rats. This procedure is not sensitive enough to measure normal ACTH-levels acurately, neither when blood was drawn from the bulbus cranialis venae jugularis, nor from the vena cubitalis. In patients having pathologically elevated ACTH-levels, the ACTH-content of plasma is significantly higher in the bulbus cranialis venae jugularis than in peripheral venous blood. An equation is presented formulating the relation of peripheral ACTH-levels, differences of ACTH-levels between bulbus cranialis venae jugularis and vena cubitalis, and of the biological halflife of endogenous ACTH. On the basis of the results of the determinations of socalled normal ACTH-levels it can be concluded, that the biological halflife of endogenous ACTH is longer than 4 min. From the data of patients with elevated ACTH-levels a halflife of approximately 40 min and a mean ACTH-secretion of approx. 100 units per day could be calculated

Ornamental plants: a summary of research, 1993-1994

Aesthetic evaluation of crabapples at the Secrest Arboretum in Wooster, Ohio: 1993-1994 / Erik A. Draper and James A. Chatfield -- Evaluation of crabapples for apple scab at the Secrest Arboretum in Wooster, Ohio: 1993-1994 / James A. Chatfield and Erik A. Draper -- The Ohio State University Water Quality Assessment Program / Mary Ann Rose, John Peterson and Laura Kramer -- Root rot of Taxus spp in Ohio caused by Phytophthora cinnamomi / Michael A. Ellis, Sally A. Miller, August F. Schmitthenner and Kenneth D. Cochran -- Winter injury on woody ornamental plants in Ohio: the winter of 1993-1994 / T. Davis Sydnor, James A. Chatfield, Randall H. Zondag, Pamela J. Bennett, Joseph F. Boggs, Kenneth D. Cochran -- Ornamental plant problems in Ohio: 1994 / James A. Chatfield, David J. Shetlar, Nancy Taylor, Joseph F. Boggs, Pamela J. Bennett, Randall H. Zondag, Michael A. Ellis, Allen Baumgard -- Ornamental plant problems in Ohio: 1993 / James A. Chatfield, Joseph F. Boggs, Paul Kauffman, David J. Shetlar, Nancy Taylor, Randall H. Zonda