new strong cement materials' chemically bonded ceramics

new cements developed in recent years have strengths that are greater by an order of magnitude than those of conventional hydraulic cements. these low-temperature materials, whose strengths approach those of many traditional high-temperature ceramics, are termed chemically bonded ceramics. the different routes to generating strong cementi..

the preparation and characterization of a ni-3 wt. percent u reference fission product source for super phenix

the fabrication and quality control of ni-3 wt. percent u (93 percent /sup 235/u) alloy rods (diameter' 8 mm, total length' 8 m) used as a reference fission product source (rfps) are described this rfps is needed for the calibration of the fuel element rupture detector which is used for the continuous monitoring of the delayed neutron act..

method for measuring the glossiness of curved surfaces using charge-coupled-device line sensor

the method for measuring the glossiness of a plane object is regulated in jis z 8741. however, no method has been established for the glossiness of a curved surface. for instance, the psychological glossiness g/sub ph/ to humans depends on the radius of curvature of the object even if the material and the surface finish are identical. how..

extreme ultraviolet explorer' mirror optical tests and results

describes a number of optical tests which were performed after each step in the fabrication process of three extreme ultraviolet explorer (euve) type 1 telescope mirrors. the surface finish and irregularity was determined by image analysis and the geometrical figure was tested interferometrically. images of a collimated point source were ..

the mirrors for the extreme ultraviolet explorer

flight mirrors for the extreme ultraviolet explorer satellite are currently under fabrication. the grazing incidence metal mirrors are wolter-schwarzschild type i and ii and are figured by diamond turning. imaging performance is excellent, with the figure after polishing for the best mirror being such that the full width-half maximum is 1..

near-infrared analysis (nira)' a technology for quantitative and qualitative analysis

the near-infrared (nir) region (defined by the astm working group on nir as 780 to 2526 nm, october 1985) was the first nonvisible portion of the spectrum to be found, in 1800, by herschel. the vibrational absorptions in the near-infrared are overtone and combination frequencies of absorption bands that occur in the mid-infrared. these ov..

growth of gaas on si and its application to fets and leds

device quality gaas layers were grown on si (100) substrates by the heat treatment of the substrates prior to the mocvd or mbe growth processes. the layers were found to have single domain structure, mirror-like surface, low epd, high electron mobility and fairly high photoluminescence intensity. small mesfets, ring oscillators, power mes..

high-temperature thermal nitridation and low-temperature electron-beam-enhanced nitridation of sio/sub 2/ thin films

surface nitridation of very thin sio/sub 2/ films ( approximately=13 nm) is achieved at low ammonia pressures by thermal activation (900 degrees c

production of surface alloys by laser irradiation

superficial incorporation of one or several species into a metallic material can be achieved by laser melting the surface of the material which has previously been covered with a coating of the alloying element(s). the alloying process involves heat transport and matter transport. simple calculations of the heat effect of the beam are eas..

sub-quarter-micrometer n-channel mosfet's fabricated with direct ion-beam nitridation

n-channel mosfets with physical gate lengths as short as 0.19 mu m were fabricated with direct e-beam writing and high-resolution pattern transfer techniques. the gate oxide thickness was 8.3 nm with a channel doping level of 1*10/sup 8/ cm/sup -3/. an ion beam nitridized film was used as a selective oxidation mask during the growth of th..