Abstract: Silicon (Si) is cast into thin shapes within a flat-bottomed graphite crucible by providing a melt of molten Si along with a relatively small amount of a molten salt, preferably NaF. The Si in the resulting melt forms a spherical pool which sinks into and is wetted by the molten salt. Under these conditions the Si will not react with any graphite to form SiC. The melt in the crucible is pressed to the desired thinness with a graphite tool at which point the tool is held until the mass in the crucible has been cooled to temperatures below the Si melting point, at which point the Si shape can be removed.

Abstract: 5-Iminodoxorubicin and its pharmaceutically acceptable acid addition salts having good antitumor activity.

Abstract: A method for forming a homogeneous bond between silicon nitride ceramics is disclosed which comprises melting a bonding composition placed between the surfaces to be bonded. The bonding composition is specifically selected to provide in the bond or joint the same chemical constituents found intergranularly in the silicon nitride materials to be bonded. The resultant bond is as strong or stronger than the silicon nitride materials bonded.

Abstract: 1,3,5,5-Tetranitrohexahydropyrimidine, termed DNNC for convenience, useful as an oxident in explosive and rocket propellant compositions.

Abstract: A flowing discharge ion source for supplying negative and positive ions to a mass spectrometer has an elongated, confined flow and discharge region through which flow the sample to be analyzed and a reagent gas and in which ionizing discharge electrodes are located. Inlet and outlet gas flow orifices are independently variable so that the reagent gas pressure in the discharge region and flow velocity therethrough are controlled. Controlling flow velocity provides one way for determining reagent and sample gas residence time, which is further controlled by making the position of the discharge electrodes adjustable along the length of the ionization region. A controllable heater is provided upstream of the discharge region to regulate reagent and sample gas temperature.

Abstract: A differential amplifying system is disclosed which includes a first section having a pair of amplifying channels comprising a pair of operational amplifiers having low noise characteristics, each of which amplifiers has an inverting input, a noninverting input, and an output terminal. Input capacitors are provided for differentially connecting an input signal to be amplified to the noninverting inputs of said pair of amplifiers. Balanced negative feedback resistance circuits are provided for connecting the output terminals of the amplifiers to their own inverting inputs. The noninverting amplifier inputs are connected to ground through a balanced pair of tapped resistance networks. Balanced positive feedback circuits, each including a resistor, connect the amplifier output terminals to the taps on the associated resistance networks for positive feedback to said noninverting amplifier inputs thereby increasing the effective input resistance of said amplifying channels.

Abstract: Described are 3'-deamino-3'-(4-methoxy-1-piperidinyl) derivatives of daunorubicin and doxorubicin having the formula ##STR1## wherein R is COCH.sub.3 or --CHOHCH.sub.3 in the case of daunorubicin derivatives, or is COCH.sub.2 OH or --CHOH--CH.sub.2 OH in the case of doxorubicin derivatives together with their pharmaceutically acceptable acid salts. The compounds have utility as antitumor agents.

Abstract: An eye tracker measures the point in space on which the eye is fixated. An input mirror reflects an input image into the eye and directs the Purkinje images so formed in the eye back into the eye tracker mechanism. The images are gathered by a collimating objective and directed through focusing and deflecting optics so as to be incident on light flux measuring devices (photodetectors). The optics and detectors are connected in closed loop servo systems which keep the first and fourth Purkinje images centered on their respective photodetectors, keep the input beam properly positioned in the eye, and at the same time generate signals responsive to movement of the first Purkinje image to give a measure of both translational and rotational horizontal and vertical eye movement and movement of the fourth Purkinje image to give a measure of purely horizontal and vertical eye movement. Circuitry combines the signals to generate a measure of purely translational horizontal and vertical signals.

Abstract: Intra-arterial blood pressure is noninvasively measured and monitored by an electromechanical force sensor which is made up of an array of individual pressure or force sensing elements, each of which has at least one dimension smaller than the lumen of the underlying artery wherein blood pressure is to be measured, and the individual pressure sensitive element used to monitor blood pressure is within one artery's diameter of the pressure sensitive element that generates the waveform of maximum pulse amplitude and generates a waveform having a spatially local minimum of at least one of the diastolic and systolic pressures.

Abstract: A deflector, through which a subject views a target or visual stimulus, can independently move the visual stimulus horizontally and vertically to stimulate or compensate the subject's eye movement and can alter the optical distance to stimulate or compensate accommodation (focus). The target is projected on the subject's eye by way of two mirrors serially disposed in the projecting path and mounted for rotation about vertical and horizontal axes, respectively. Lens elements produce an undistorted unity magnification image of the eye at each mirror, with the center or rotation of the eye in each image nominally on the axis of rotation of the respective mirrors, and servo motors independently rotate the mirrors about their respective axes to produce vertical and/or horizontal deflection of the stimulus at the eye.

Abstract: Essentially nonreflective coupling for ultrasonic waves is provided between a fluid medium confined in a rigid container and a biological specimen, such as a human body, through a container closing bellows system which incorporates a thin, flexible closing membrane that contacts and conforms to the contours of the specimen. A supportive bellows system between rigid parts of the fluid container and the membrane gives the membrane the essential properties of conforming to the contours of a specimen having variations in curvature (concavities and convexities) while having the ability to contain the fluid medium without rupture or undue distension when it is not supported externally, as by contact with the specimen. The supportive bellows system utilizes a pair of flexible toroidal members, one tubular and one U-shaped in cross section, attached to one another in series and having internal venting so that pressure within the toroids is governed by the pressure of the fluid inside the coupling bellows system.

Abstract: Composite acoustic lens assemblies which are adapted for use in a fluid medium and utilized for forming acoustic images with incident acoustic waves or focusing incident acoustic waves are constructed utilizing two or more lens elements with a fluid filler medium contained therebetween. In order to reduce the radius of curvature of the lens elements to such an extent that mode conversion at liquid/solid interfaces is substantially eliminated while providing the required image or focusing, the materials of the lens medium and the liquid medium between the lens elements are selected so that the velocity of propagation of acoustic waves in the medium, at least on one side of the composite acoustic lens is intermediate the velocity of propagation of acoustic waves in the media of the lens elements and the fluid filler.

Abstract: An ultrasonic transducer comprising a linear array of piezoelectric elements for converting a single line from a compressional acoustic image field to electrical impulses which, in turn, provide a means for converting the incident compressional image field to a visual representation. In order to match the configuration of the acoustic image field, the array of piezoelectric elements, in a preferred embodiment, has the configuration of an arc, that is, the array is arranged in a straight line in one plane and in an arc in a plane orthogonal to the first. The transducer is made up of a plurality of assemblies each of which is composed of segments of piezoelectric material each held in a supporting slot in a length of metal plate which slot is filled with a material selected to provide impedance matching between the piezoelectric material and the transmission medium.

Abstract: Velocity of a gas (e.g., wind) is determined as a function of the pulse repetition frequency of corona discharge (Trichel) pulses from a discharge probe positioned in the gas stream.