Abstract: A dosimeter for collecting vapors and gases of hydrazine and of hazardous derivatives of hydrazine such as monomethylhydrazine and 1,1-dimethylhydrazine, employs a housing with a perforated cover. Situated inside the housing is a removable disk on which is coated a solution of citric acid in methanol. The solution initially contains 20% to 30% of citric acid monohydrate dissolved in methanol and the solution is permitted to age for seven or eight days before being coated on to the disk.

Abstract: An optical strain gauge has a first birefringent optical module secured to a specimen bar in a manner transferring tensile strain from the bar to the module and has a similar second birefringent module secured to the bar in a manner transferring shear strain from the bar to the module. The two modules are disposed in series in a light path along which polarized light is directed. A polarization rotator is situated in that path between the two modules and causes the phase shift between two polarized components of the light to optically subtract. The optical subtraction arrangement conduces to making the gauge insensitive to environmental effects because stresses imposed by those environmetal effects equally upon both modules result in optical cancellation of the effects of those stresses on the modules. Those two polarized components, after passing through both modules, are separated to obtain a measure of the difference between the transferred tensile strength and the transferred shear strain.

Abstract: A highly sensitive magnetometer employs a magnetostrictive amorphous metal core in which a piezoelectric driver induces stress variations. In the presence of an external magnetic field, the magnetization of the magnetostrictive core varies in relation to the induced stress. The amplitude of the variations in magnetization is proportional to the strength of the external field and is sensed by a pick-up winding disposed around the magnetostrictive core. The dynamic range of the device is improved by employing a bucking field winding around the core to null out the magnetization of the core. In contrast to the inherent non-linear characteristic of the conventional fluxgate magnetometer, the invention inherently provides a linear response to magnetic field strength.

Abstract: A magnetic field sensing transducer which converts magnetic field intensity into a magnetostrictive strain and transfers that strain to an optical fiber employs a thin wall, hollow, cylindrical shell around which is wound a ribbon of an amorphous metallic magnetostrictive material. In another embodiment, the entire shell is formed by turns of the ribbon of magnetostrictive material. The optical fiber is coiled around the magnetostrictive cylinder formed by the wound ribbon and at both its ends, the optical fiber is affixed to the shell. The shell is covered at both its ends by caps and forms a thin wall resonator having three normal axisymmetric modes of vibration. The torsional vibratory mode is here of no interest because it does not appreciably couple to the optical fiber. Any one of the other two axisymmetric modes of vibration can be made dominant by selection of the appropriate length to radius ratio of the cylindrical shell.

Abstract: A fluoroacrylate ester monomer having the formula: ##STR1## wherein R.sub.1 and R.sub.2 are independently selected from the group consisting of saturated aliphatic hydrocarbons having from 1 to about 3 carbon atoms and R.sub.3 is selected from the group consisting of hydrogen and methyl. The monomer has a water-repellent "umbrella" of 3 gem bis trifluoromethyl groups around the acrylate monomer which do not interfere with the acrylate properties. Polymerization of the monomer results in a stable, exceptionally hydrophobic, linear thermoplastic polymer. The invention also includes processes for making the monomer from a diether halide and certain novel intermediates.

Abstract: A fluoroacrylate ester monomer having the formula: ##STR1## wherein R.sub.1 and R.sub.2 are independently selected from the group consisting of saturated aliphatic hydrocarbons having from 1 to about 3 carbon atoms and R.sub.3 is selected from the group consisting of hydrogen and methyl. The monomer has a water-repellent "umbrella" of 3 gem bis trifluoromethyl groups around the acrylate monomer which do not interfere with the acrylate properties. Polymerization of the monomer results in a stable, exceptionally hydrophobic, linear thermoplastic polymer. The invention also includes processes for making the monomer from a diether halide and certain novel intermediates.

Abstract: An instrument for measuring stress is arranged to be insensitive to stresses caused by conditions other than that of the phenomenon to be measured. The instrument employs two equal lengths of optical fibers of the kind exhibiting birefringence when stressed. Polarized light is directed into one of the optical fibers along its longitudinal axis. The two optical fibers are arranged in series with respect to the longitudinal transmission of the polarized light through those fibers. A polarization rotator is situated in the light path between the two optical fibers. The polarized light transmitted through the polarization rotator is rotated by an amount causing stresses imposed equally on the two optical fibers to have equal and opposite effects of the transmitted polarized light.

Abstract: A method of making fluoride glasses produces fluoride glass having such low OH and low oxide content that the extrinsic optical absorbance caused by the OH vibration at 2.9.mu. is eliminated or substantially reduced. In the method, a glass charge is placed in a capped crucible and dry argon gas is caused to flow through the capped crucible while the temperature is raised to melt the charge. Thereafter, while the dry argon gas flow is continued, the temperature in the furnace is held constant for a time sufficient to obtain a homogenous melt in which all crystalline materials are dissolved. The temperature is then lowered to a value between the glass crystalization temperature and the sublimation temperature of ZrF.sub.4 and then, at isothermal conditions, the flow of dry argon gas is replaced by a flow of SF.sub.6 gas or by a flow of CF.sub.4 gas. At the lowered temperature, the SF.sub.6 or CF.sub.4 gas flow is maintained for a time sufficient to eliminate or greatly reduce OH and oxides in the glass melt.

Abstract: A signal processor is arranged to process polarized light signals obtained from a stress sensor of the type having a photoelastic element that responds to stress by causing a phase difference between components of the polarized light propagating through that element. The stress sensor provides two output beams, each of which has a different polarized component of the transmitted light. The signal processor employs a pair of photodetectors which respond to the intensities of the two polarized light beams by converting the polarized light into electrical signals. Those two electrical signals provide the inputs to a difference differentiator that provides an output proportional to the difference between the derivatives of the inputs. The two electrical output signals of the photodetectors are also applied as inputs to a multiplier whose output is related to the product of its inputs.

Abstract: A broad band dipole antenna of short length is formed by two tubular linear radiators which are spaced apart at their adjacent inner ends. Each of the radiators is encased in an electrically insulative sleeve and the antenna is liquid loaded along its length by a jacket of conductive fluid disposed between the insulative sleeve and an insulative tubular housing surrounding the radiators. The dipole is center-fed and each of the radiators, at its outer end, terminates in a connection to one end of a lumped resistive load whose other end is connected to a conductive disk that is in contact with the conductive liquid.

Abstract: An ignition device of the plasma jet type is disclosed. The device has a cylindrical cavity formed in insulating material with an electrode at one end. The other end of the cylindrical cavity is closed by a metal plate with a small orifice in the center which plate serves as a second electrode. An arc jumping between the first electrode and the orifice plate causes the formation of a highly-ionized plasma in the cavity which is ejected through the orifice into the engine cylinder area to ignite the main fuel mixture.Two improvements are disclosed to enhance the operation of the device and the length of the plasma plume. One improvement is a metal hydride ring which is inserted in the cavity next to the first electrode. During operation, the high temperature in the cavity and the highly excited nature of the plasma breaks down the metal hydride, liberating hydrogen which acts as an additional fuel to help plasma formation.