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Laser desorption Fourier transform mass spectrometry (LD/FTMS) was used to obtain mass spectra of bradykinin, Lys-bradykinin, and Met-Lys-bradykinin. With poly(ethylene glycol) as an external mass standard, absolute errors for mass measurement accuracy averaging 2–7 ppm were obtained for the major ions of the bradykinins. Similar absolute errors for mass measurement accuracy were obtained when poly(ethylene glycol) was used as an internal standard. Mass measurement accuracy was investigated and applicability of the measurements to elemental composition assignments examined. Present results are compared with previous field desorption, secondary ion mass spectrometry, and fast atom bombardment spectra of bradykinins.

We have demonstrated that T lymphocytes from the spleens of adult guinea pigs sensitized to group A streptococcal antigens are cytotoxic for cultured fetal guinea pig heart cells. Lymphocyte cytotoxicity, measured by 51Cr release from target cells, was stimulated by sensitization in vivo with group A whole cells, cell walls, and purified protoplast membranes emulsified with complete Freund's adjuvant (CFA). Sensitization with group C streptococcal antigens in CFA or CFA alone produced lymphocytes with little or no specific cytotoxic activity. Target cells of cultured fetal skeletal muscle, liver, or skin were relatively refractory to effector cell cytotoxicity. The presence of antigenic determinants on the membranes of cultured myofibers, cross-reacting with group A streptococcal cellular antigens, was confirmed by immunofluorescence. These data are discussed in terms of a model for poststreptococcal rheumatic myocarditis in which cell-mediated autoimmune mechanisms may participate.

With a proper choice of coordinates and for certain substances over a limited temperature range, the information contained in a whole family of adsorption isotherms coalesces into a single universal curve. Such behaviour can be related to a particularly simple thermodynamic model. This model and some of its implications are explored in detail. In particular, thermodynamic internal self-consistency demands that there be a unique (generally non-linear) relationship between the mass adsorbed and the film thickness which is completely deducible from measured adsorption isotherms plus bulk thermodynamic data. It is independent of assumptions regarding the form of the van der Waals attraction binding the adsorbate to the adsorbent substrate. The integral equation embodying this relationship is derived and exhibited. As an example of its use the equation is applied to the case of thin films of helium II.

Investigation results on stress waves generated by Q-switched ruby laser irradiated thin metal films under confinement, studied over a wide range of film materials and film thicknesses, are reviewed. The results indicate that the dependence on these parameters is much weaker than is predicted by heat transfer estimations commonly used to describe the interaction of laser irradiation with unconfined bulk-solid surfaces.

The results of experiments characterizing CuInSe2 deposition by reactive magnetron sputtering and by a hybrid sputtering and evaporation technique are presented. Both techniques produce films with chemical and structural properties comparable with those commonly used for polycrystalline CuInSe2-based solar cells. The reactive sputtering technique produces films with compositions ranging from copper rich to indium rich with near-stoichiometric selenium contents at low temperatures. Indium-rich films cannot be produced at temperatures above about 400°C. The hybrid process produces films over a large composition range at growth temperatures up to 450°C. Film compositions are uniform across 25 mm substrates to within ±1 at.% and non-uniformities can be directly related to the deposition geometry. For hybrid films, the selenium flux is shown to play a major role in determining both the selenium and the indium contents of the films at elevated temperatures. A coupled In-Se desorption mechanism which is inhibited by the presence of large amounts of excess selenium is proposed to explain the latter data. The substrate material is shown to affect strongly the film chemistry. Films deposited on copper show a higher copper content due to diffusion of the substrate material into the film during growth. Layers deposited by the hybrid process on molybdenum exhibit lower indium and higher selenium contents than films on glass at all temperatures examined. Finally, copper, indium and selenium diffusion into molybdenum substrates was observed at all growth temperatures.

The test results of 320 units of a laser initiated microdetonator are summarized. The commercially fabricated units used a lead styphnate/lead azide/HMX (1 mg/13.5 mg) explosive train design contained in a miniature aluminum can that was capped with a glass-metal seal window. The test parameters were the laser energy, temperature, laser pulse duration, laser wavelength and nuclear radiation (5,000,000 rad of 1 MeV gamma rays). The performance parameters were the laser energy for ignition and the actuation response time.

Positive and negative ion laser desorption Fourier transform mass spectra of ascorbic acid, isoascorbic acid, and their sodium and potassium salts have been determined. A number of differences between these spectra and previously reported laser microprobe mass analyzer (LAMMA) spectra are found. In contrast with earlier results, m/z 175 anions are present in all negative ion spectra, as are cluster ions. Thus, it should not be concluded that the radical salts are electroneutral, as claimed in the earlier study.

The resonant frequency of a quartz crystal oscillating in the thickness-shear mode changes by virtue of the mass loading due to any type of film laid down on its surfaces. For a helium film only the normal fraction remains rigidly coupled to the substrate motion. Adsorption isotherms of He-4 measured with this technique show clear departures from conventional nonsuperfluid behavior. We attribute this effect to the onset and presence of superfluidity in the film.

The rate of crystallization of supercooled water in cylindrical tubes is determined. It is found that the rate depends on the tube diameter, on the degree of supercooling, and on the thermal conductivity of the wall, but in no simple way. It is shown that no one mechanism of crystallization can account for the growth curves obtained but that a competing process between the heat conduction through the tube wall and the kinetic behavior of the liquid molecules must be considered. The various ice structures observed during the experiment are reported, along with their possible correlation with the observed growth rates.

Immediate longitudinal detonations have been observed in confined small-diameter columns of PETN, RDX, and tetryl by using a focused Q-switched ruby laser. The energy ranged from 0.8 to 4.0 J in a pulse width of 25 nsec. A 1000-A-thick aluminum film deposited on a glass window was used to generate a shock wave at the window-explosive interface when irradiated by the laser. In some cases, steady-state detonations were reached in less than .5 microsec with less than 10% variation in the detonation velocity.

Erythroderma and exfoliative dermatitis developed in a 17-year-old boy following therapy with phenytoin sodium. Immunologic studies performed early in the course of the dermatitis disclosed panhypogammaglobulinemia and a marked increase in T lymphocytes that responded poorly in vitro to T-cell mitogens. After therapy with prednisone, the dermatitis improved somewhat, and the patient's lymphocytes proliferated in vitro when exposed to phenytoin. We speculate that our patient's acute hypersensitivity reaction may have been mediated by an excessive number of phenytoin-sensitized suppressor-cytotoxic T lymphocytes and may represent a disorder of immunoregulatory T cells.

The resonant frequency of a thickness-shear mode oscillating quartz crystal is lowered by virtue of the mass loading of any film laid down on its surfaces.1,2 For a uniformly deposited, thin solid film with thickness less than 1% or so of the crystal thickness this change Δf, is given by the formula $$ - \Delta f = 2(2{f^2}/c{\rho _q})\sigma $$ (1) Here σ represents that part of the mass per unit area which remains rigidly coupled to the substrate motion, f is the resonant frequency, c is the shear wave velocity in the crystal, and ρ q is the density of the quartz.

Corrugated ducts are commonly used in compact heat exchangers because of their efficient heat exchange capabilities. Here, the numerical prediction of transitional characteristics of fluid flow and heat transfer in periodic fully developed corrugated duct is carried out by using a Lam-Bremhorst low Reynolds number turbulence model. Computations were performed for Prandtl number of 0.7, in the Reynolds number range of 100 to 2500, for corrugation angles of {theta} = 15 and 30{degree}, and for three interwall spacings. The predicted transitional Reynolds number is lower than the value for the parallel plate duct and it decreases with increasing corrugation angle. Experiments were also performed for pressure drop measurements and for flow visualization and the results were compared with the numerical predictions.

Dielectric breakdown in shock‐loaded x‐cut quartz is examined under conditions of both impact loading and Q‐switched laser‐irradiation loading. It is observed that breakdown is characterized by an inherent time delay which depends on the magnitude of the electric field. For pulse duration less than about 30 ns, dielectric breakdown is not observed.