R-phase formation in Ti39Ni45Cu16 shape memory thin films and bulk alloys discovered by combinatorial methods

The combinatorial fabrication and high-throughput characterization of a Ti–Ni–Cu shape memory thin film composition spread led to the discovery of the shape memory alloy Ti₃₉Ni₄₅Cu₁₆, which exhibits a single B2 → R-phase transformation above 25 °C with a thermal hysteresis width <1 K. Here we show that the thin film results correctly predict the phase transformation behavior of bulk material upon cooling from the high temperature phase. For both thin film and bulk, a two-step B2 → R-phase → B19′ transformation was found. The B2 → R-phase transformation can be exploited independently, due to a significant temperature separation of the two transformation steps. The shape memory effect in both thin film and bulk samples is limited due to the two-phase microstructure. Transmission electron microscopy investigations revealed the existence of Ti(Ni,Cu)₂ precipitates within the TiNi(Cu) matrix, which are concluded to be responsible for the R-phase formation and separation of the transformation steps.     

Glycerol gangliotomy of the second dorsal cervical root in rats: an experimental study to evaluate a minimal invasive approach for the treatment of the chronic cervicogenic headache

The purpose of this integrated literature review (1980-1997) is to describe and summarize specific nursing interventions that have been devised to aid community-dwelling older adults with self-administration of prescribed medications. Interventions that combine patient education with written information or follow-up phone calls produce the most positive results. By using interventions supported by research, nurses will provide more effective and efficient care to older adults managing medications at home.     

Derivation of surface soil moisture from ENVISAT ASAR wide swath and image mode data in agricultural areas

Water and energy fluxes at the interface between the land surface and atmosphere are strongly dependent on surface soil moisture content, which is highly variable in space and time. It has been shown in numerous studies that microwave remote sensing can provide spatially distributed patterns of surface soil moisture. In order to use remote-sensing-derived soil moisture information for practical applications as, for example, flood forecasting and water balance modeling in mesoscale areas, frequent large-area coverage is a prerequisite. New sensor generations such as ENVISAT Advanced Synthetic Aperture Radar (ASAR) or RADARSAT allow for image acquisitions in different imaging modes and geometries. Imaging modes with the capability of large-area coverage, such as the Wide Swath Mode of ENVISAT ASAR, are of special interest for practical applications in this context. This paper presents a semiempirical soil moisture inversion scheme for ENVISAT ASAR data. Different land cover types as well as mixed-image pixels are taken into account in the soil moisture retrieval process. The inversion results are validated against in situ measurements, and a sensitivity analysis of the model is conducted.     

Quantitative measurement of voids formed during liquid impregnation of nonwoven multifilament glass networks using an optical visualization technique

A technique based on matching the refractive index of an invading liquid to that of a fiber mat has been used to study entrapment of air (“voids”) that occurs during forced in-plane radial flow into nonwoven multifilament glass networks. The usefulness of this technique is demonstrated in quantifying and mapping the air pockets. Experiments with a series of fluids, with surface tensions varying from 28 × 10^?3 to 36 × 10^?3 N/m, viscosities from 45 × 10^?3 to 80 × 10^?3 Pa · s, and inlet flow rates from 0.15 × 10^?6 to 0.75 × 10^?6 m³/s, have shown that void content is a function of the capillary number characterizing the flow process. A critical value of capillary number Ca = 2.5 × 10^?3 identifies a zone below which void content increases exponentially with decreasing capillary number. Above this critical value, negligible entrapment of voids is observed.     

Video analysis of DNA sequence homologies.

A method for the rapid quantitative analysis of dot blot assays is presented. A video camera, an NTSC compatible frame grabber board, and an AT personal computer are used to read photographic exposures of the assay plate. Image processing and image analysis techniques are used to calculate the orientation of the dot raster and then to compensate for the effect of variations in field illumination on measurements of local contrast. Local contrast (between dots and background) is an exponential function of the amount of hybridization between blotted DNA and complimentary oligonucleotide probes. The amount of hybridization between blotted DNA and oligonucleotide probes of known sequence is the criteria used to establish HLA-DR tissue types. Although the assay described here utilizes a chemiluminescent reaction, this algorithm may be used to read any assay that produces a rectangular raster of dots.     

Modeling of Conductivity Versus Density Behavior in Green-State Powder Metallurgy Compacts

Ongoing research at Worcester Polytechnic Institute (WPI) has recently resulted in the development of an electrostatic multipin instrument capable of testing green-state compacts directly after compaction. By monitoring a steady electric current flow through the sample and recording the voltages over the surface valuable information is gathered, leading to the prediction of the structural health of the green-state parts. Whereas our prior work concentrated on the detection of surface-breaking and subsurface defects, which requires the determination of large differences in material properties over small flaw sizes, the results presented in this paper aim at the density prediction throughout the volume of the sample. This requires the detection of small changes in material properties over large regions. A physical model and a mathematical formulation are reported, which are capable of relating green-state density changes to electric conductivity in the presence of various lubricant concentrations. Preliminary electrostatic measurements of cylindrical compacts have thus far confirmed the theoretical model assumptions, showing that the electric conductivity follows a complex graphical behavior that is determined by the type and concentration of the lubricant. Specifically, the green state conductivity increases as the sample density increases up to values of approximately 6.9 to 7.0 g/cm³. Any further density increase, however, results in a decrease in conductivity.     

Thermodynamics and Phase Equilibria in the Ca─Cu─O System

Phase equilibria in the CaO─CuO─Cu system were determined at 1173 K from the results of X-ray diffraction measurements using specimens annealed in the oxygen partial pressure range from P O₂= 1 to 10⁻⁸ atm. Electromotive force (emf) measurements using ZrO₂ solid electrolyte cells were carried out in the ternary phase equilibria. Gibbs free energies for the chemical reactions were summarized by equations with linear temperature dependence, and the standard free energy of formation for Ca₂CuO₃ was derived. The stability conditions of the oxides are displayed in the p – T – x diagram, and the possible phase equilibria with the liquid are evaluated.     

Beitr?ge zur Untersuchung und Beurteilung von Fruchts?ften

Ohne ZusammenfassungMitteilung aus der Chemischen Untersuchungsanstalt der Stadt Leipzig.