Investigation of the Operating Properties of the Leakage Current Anemometer

Investigation of the Operating Properties of the Leakage Current Anemometer

Date: October 1, 1947
Creator: Fucks, Wilhelm
Description: Freedom from inertia, erosion of electrodes, and reaction make the leakage current particularly appropriate for the measurement of flow velocities in gases. Apparatus previously described has now been improved by reducing the size of the electrodes by one -thousandth, as is necessary aerodynamically, and by increasing the magnitude of the current from 1000 to 10,000 times; the latter result was obtained.by use of mercury high-pressure lamps set up at the one focal point of an ellipsoidal reflector with the cathodes arranged at the other focal point or by use of suitable X-ray radiation. Families of calibration curves were taken with a number of vivid tests conditions of the greatest variety and the operating properties of the instrument were widely elucidated by calculation of the sensitivity to fluctuation; this was done at first for operation at stationary conditions only; due to the freedom from inertia the instationary conditions were thus also given. Accordingly, the leakage current anemometer ought to be appropriate for investigations of turbulence,.
Contributing Partner: UNT Libraries Government Documents Department
Determination of the Actual Contact Surface of a Brush Contact

Determination of the Actual Contact Surface of a Brush Contact

Date: August 1, 1944
Creator: Holm, Ragnar
Description: The number of partial contact surfaces of a brush-ring contact is measured by means of a statistical method. The particular brush is fitted with wicks - that is, insulated and cemented cylinders of brush material, terminating in the brush surface. The number of partial contact surfaces can be computed from the length of the rest periods in which such wicks remain without current. Resistance measurements enable the determination of the size of the contact surfaces. The pressure in the actual contact surface of a recently bedded brush is found to be not much lower than the Brinell hardness of the brush.
Contributing Partner: UNT Libraries Government Documents Department
Piezoelectric Instruments of High Natural Frequency Vibration Characteristics and Protection Against Interference by Mass Forces

Piezoelectric Instruments of High Natural Frequency Vibration Characteristics and Protection Against Interference by Mass Forces

Date: February 1, 1943
Creator: Gohlka, Werner
Description: The exploration of the processes accompanying engine combustion demands quick-responding pressure-recording instruments, among which the piezoelectric type has found widespread use because of its especially propitious properties as vibration-recording instruments for high frequencies. Lacking appropriate test methods, the potential errors of piezoelectric recorders in dynamic measurements could only be estimated up to now. In the present report a test method is described by means of which the resonance curves of the piezoelectric pickup can be determined; hence an instrumental appraisal of the vibration characteristics of piezoelectric recorders is obtainable.
Contributing Partner: UNT Libraries Government Documents Department
A 018μm Cmos Transmitter for Ecg Signals

A 018μm Cmos Transmitter for Ecg Signals

Date: December 2013
Creator: Kakarna, Tejaswi
Description: Electrocardiography (ECG) signal transmitter is the device used to transmit the electrical signals of the heart to the remote machine. These electrical signals are ECG signals caused due to electrical activities in the heart. ECG signals have very low amplitude and frequency; hence amplification of the signals is needed to strengthen the signal. Conversion of the amplified signal into digital information and transmitting that information without losing any data is the key. This information is further used in monitoring the heart.
Contributing Partner: UNT Libraries
An Innovative Project and Design Oriented Electrical Engineering Curriculum at the University of North Texas

An Innovative Project and Design Oriented Electrical Engineering Curriculum at the University of North Texas

Date: Summer 2011
Creator: Garcia, Oscar N.; Varanasi, Murali R.; Acevedo, Miguel F. & Guturu, Parthasarathy
Description: Article discussing an innovative project and design oriented electrical engineering curriculum at the University of North Texas.
Contributing Partner: UNT College of Engineering
Safety Rules for the Installation and Maintenance of Electrical Supply and Communication Lines

Safety Rules for the Installation and Maintenance of Electrical Supply and Communication Lines

Date: April 15, 1927
Creator: United States. Bureau of Standards.
Description: Report containing information regarding "the construction and maintenance of overhead and underground electrical supply and communication lines" (p. ii).
Contributing Partner: UNT Libraries Government Documents Department
Executive Correspondence – Letter dtd 08/02/05 to the Commission from UCLA Professor of Electrical Engineering Tatsuoh Itoh

Executive Correspondence – Letter dtd 08/02/05 to the Commission from UCLA Professor of Electrical Engineering Tatsuoh Itoh

Date: August 11, 2005
Creator: unknown
Description: Executive Correspondence – Letter dtd 08/02/05 to the Commission from UCLA Professor of Electrical Engineering Tatsuoh Itoh criticizing DoD’s recommendation to move the Army Research Office (ARO) from North Carolina to Bethesda, MD and explaining how such a move would severely compromise ARO’s ability to provide revolutionary advances to the Army.
Contributing Partner: UNT Libraries Government Documents Department
Executive Correspondence – Letter received 08/08/05 by the BRAC Commission from Princeton University Professor of Electrical Engineering Daniel C. Tsui

Executive Correspondence – Letter received 08/08/05 by the BRAC Commission from Princeton University Professor of Electrical Engineering Daniel C. Tsui

Date: August 11, 2005
Creator: unknown
Description: Executive Correspondence – Letter received 08/08/05 by the BRAC Commission from Princeton University Professor of Electrical Engineering Daniel C. Tsui criticizing DoD’s recommendation to move the Army Research Office (ARO) from North Carolina to Bethesda, MD and explaining how such a move would severely compromise ARO’s ability to provide revolutionary advances to the Army.
Contributing Partner: UNT Libraries Government Documents Department
Employment of dual frequency excitation method to improve the accuracy of an optical current sensor, by measuring both current and temperature.

Employment of dual frequency excitation method to improve the accuracy of an optical current sensor, by measuring both current and temperature.

Date: December 2008
Creator: Karri, Avinash
Description: Optical current sensors (OCSs) are initially developed to measure relatively large current over a wide range of frequency band. They are also used as protective devices in the event a fault occurs due to a short circuit, in the power generation and distribution industries. The basic principal used in OCS is the Faraday effect. When a light guiding faraday medium is placed in a magnetic field which is produced by the current flowing in the conductor around the magnetic core, the plane of polarization of the linearly polarized light is rotated. The angle of rotation is proportional to the magnetic field strength, proportionality constant and the interaction length. The proportionality constant is the Verdet constant V (λ, T), which is dependent on both temperature and wavelength of the light. Opto electrical methods are used to measure the angle of rotation of the polarization plane. By measuring the angle the current flowing in the current carrying conductor can be calculated. But the accuracy of the OCS is lost of the angle of rotation of the polarization plane is dependent on the Verdet constant, apart from the magnetic field strength. As temperature increases the Verdet constant decreases, so the angle of rotation ...
Contributing Partner: UNT Libraries
Electro-surgical unit, portable.

Electro-surgical unit, portable.

Date: August 30, 1944
Creator: United States. War Dept.
Description: A guide to the assembly, operation, maintenance, and packing of the Portable Electro-Surgical Unit issued by the Army Medical Department.
Contributing Partner: UNT Libraries Government Documents Department
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