High temperature solder device for flat cables

A high temperature solder device for flat cables includes a microwelder, an anvil which acts as a heat sink and supports a flexible flat ribbon cable that is to be connected to a multiple pin connector. The microwelder is made from a modified commercially available resistance welding machine such as the Split Tip Electrode microwelder by Weltek, which consists of two separate electrode halves with a removable dielectric spacer in between. The microwelder is not used to weld the items together, but to provide a controlled compressive force on, and energy pulse to, a solder preform placed between a pin of the connector and a conductor of the flexible flat ribbon cable. When the microwelder is operated, an electric pulse will flow down one electrode, through the solder preform and back up the other electrode. This pulse of electrical energy will cause the solder preform to heat up and melt, joining the pin and conductor

Apparatus for measuring static coefficient of friction under compressive loads

Device includes load cell attached to rigid structure. Crosshead directly beneath cell is connected to constant-speed electrical motor. Crossarm supported by crosshead serves as platform on which bodies are tested. Test data are recorded on X-Y recorder which is connected to load cell and motor

Static coefficient test method and apparatus

The static coefficient of friction between contacting surfaces of a plurality of bodies is determined by applying a load to the bodies in a direction normal to the contacting surfaces. Opposite ends of a flexible filament are connected to a load cell and the first of the bodies. A motor continuously moves the second of the bodies away from the load cell at constant velocity at right angles to the force of the normal load so that the first body moves intermittently relative to the second body across a contact surface between them. The load on the surfaces, the nature of the surfaces, and the speed of the first body relative to the load cell are such that the filament is alternately and cyclically tensioned and relaxed as the movement occurs. The maximum tension occurs at the incipient stages of movement of the first body relative to the second body. The load cell derives a series of measurements which are coupled to an x-y recorder, from which the maximum forces of the filament are determined to enable the static coefficient of friction to be determined. From the maximum forces and the normal force, the coefficient is determined. For determining coefficients of friction where there are large compression loads, the normal load is applied with a calibrated compression spring that is deflected by a predetermined amount determined by a spring load vs. deflection calibration curve

Peen plating

A process for metal plating which comprises spraying a mixture of metallic powder and small peening particles at high velocity against a surface is described. The velocity must be sufficient to impact and bond metallic powder onto the surface. In the case of metal surfaces, the process has as one of its advantages providing mechanical working (hardening) of the surface simultaneously with the metal plating

Plating by glass-bead peening

Technique permits plating of primarily metallic substrates with either metals or nonmetals at normal temperature. Peening uses compressed air to apply concurrent streams of small glass beads and powdered plating material to the substrate

Mechanical properties of Skylab thermal shield materials after prolonged ultraviolet irradiation

In response to an emergency request, the mechanical properties of two complex laminate materials, used as thermal shields on the Skylab spacecraft, were investigated. Concern over the prolonged use of these materials in the space environment prompted this investigation. Shields made of both of these materials, popularly called the parasol and the sail types, were taken to the Skylab spacecraft by the original Skylab astronauts. Both were used to restore thermal control after the original control surfaces were damaged during launch. During the tests the tensile properties were measured at anticipated service temperature and after prolonged exposure to increasing degrees of ultraviolet radiation at intensities approaching two solar constants. Some samples received exposures equivalent to 2,350 hours. The performance and degradation of the two materials are presented in terms of orientation, vacuum, and degree of irradiation. In general, the 75-micron (3-mil) parasol laminate showed a decrease in tensile properties as a function of exposure time, while the 200-micron (8-mil) sail laminate was little affected by exposure to the ultraviolet radiation

Intranasal sodium citrate solution improves olfaction in post-viral hyposmia

Background: Calcium plays an integral role in olfactory signal transduction, including feedback inhibition. Sodium citrate acts as a calcium sequestrant and when applied intranasally, reduces free calcium available for feedback inhibition, which should theoretically improve olfaction. We aimed to investigate the utility of intranasal sodium citrate in improving the olfactory function of hyposmic patients, by performing this prospective placebo controlled, single-blinded trial. Methodology: Monorhinal olfactory testing for odour identification and threshold was performed in hyposmic patients using “Sniffin’ Sticks”, before and after treatment. Treatment consisted of sodium citrate solution application to the olfactory cleft. Sodium chloride solution was applied to the contralateral olfactory cleft, which therefore acted as placebo control. Patients were blinded to the side of sodium citrate application, and side of treatment was randomized between patients. Results: 57 patients participated in the trial, aged 22-79. Causes of hyposmia included: post-viral (7); posttraumatic (10); sinonasal (30) and idiopathic (10). Compared with placebo, there was significant improvement in the identification scores of participants with post-viral hyposmia, following sodium citrate treatment. No significant change in olfactory function occurred for either identification or threshold in any other aetiological subgroup. Conclusions: Intranasal sodium citrate may be of benefit to patients with post-viral hyposmia

Non Destructive Characterization of Oxide Dispersion Strengthened Steels

Various complementary NDT methods have been used for the characterization of oxide dispersion strengthened steels. Complex microstructure of these materials requires multi technique approach in order to better understand the effects of different nanostructures in specific environmental conditions. All techniques used in the experiment, namely positron annihilation lifetime spectroscopy (PAS), small angle neutron spectroscopy (SANS), thermoelectric power (TEP) and Barkhausen noise (BN) measurements, are sensitive to spectrum of defects in nano/micro metric range. Present report discusses feasibility of application of individual techniques on investigation of ODS materials and some degradation mechanisms. In particular, 475°C embrittlement of high-Cr ODS was studied. Precipitation of Cr-rich phase, responsible here for severe degradation of material properties, was experimentally observed by SANS as a new scattering type of ~ 2nm scattering centres in the microstructure of thermally aged materials. The same process was observed in TEP as the increase of relative Seebeck coefficient and the new precipitates were found to act as a pining site for magnetic domain wall movement by the Barkhausen noise measurement. Although the precipitation of α’ phase does not change positron lifetime spectra directly, our experiments shown their non trivial effect on the lifetime parameters. Substantially different behaviour of vacancy type defects was observed in the embrittled high-Cr ODS materials, than in the 9%Cr ODS aged at the same conditions. Present results provide important guidelines for future irradiation experiments and application of the NDT on the material characterization.JRC.F.4-Nuclear Reactor Integrity Assessment and Knowledge Managemen

Microstructural Evolution of Cr-Rich ODS Steels as a Function of Heat Treatment at 475°C

In the current research, the effect of heat treatment on the morphology of the dispersoids and their phase composition were investigated in three Cr-rich ferritic oxide dispersion strengthened (ODS) steels: PM2000, MA956, and ODM751. The steels were aged at 475°C for times ranging from 100 to 1,000 h. The microstructure was characterized using transmission electron microscopy. Study of the as-recrystallized samples revealed nano-scale Y–Al–O complex-oxide particles dispersed in the ferritic matrix. These dispersoids, which differ in size (10–160 nm) and geometry (polygonal and spherical), were identified as Y4Al2O9, YAlO3, and Y3Al5O12. After heat treatment, a significant change in the morphology, size, and distribution of the dispersoids was observed. Changes in the phase composition of the oxide dispersoids were also observed: YAlO3 (with perovskite structure) was identified as the most dominant phase, indicating that it is probably the most stable phase in the Cr-rich ferritic ODS steels.JRC.F.4-Nuclear Reactor Integrity Assessment and Knowledge Managemen