HRTEM observation of the monoclinic-to-tetragonal m-t) phase transition in nanocrystalline ZrO2

The orientation relations m(100) || t(001), m[001] || t[110]; m(011) || t(100), m[100] || t[001]; m(100) || t(110), m[001] || t[001]; m(013) || t(116), m[001] || t[001] (indices for the primitive tetragonal cell) have been found between the tetragonal (t) and monoclinic (m) domains during the electron irradiation-induced m-t phase transition observed in-situ with HREM within isolated zirconia nanoparticles. Geometric models of the m-t interfaces are proposed.     

Study of phase equilibria in the Al - Pd - Re system

Scanning and transmission electron microscopy have been combined with x-ray diffraction to examine the phase equilibria in the Al - Pd - Re system at 1000°C for compositions from 50 to 100 at.% Al, and the corresponding isothermal section has been constructed. The binary monoclinic Al₃ Re phase has been observed for the first time. It is confirmed that there is a stable icosahedral phase in this system. The boundaries to its homogeneity region have been determined and the phase equilibria in which it participates.     

Potency comparison of peptidomimetic inhibitors against HIV-1 and HIV-2 proteinases: design of equipotent lead compounds

The results of investigation of haptoglobin (Hp) types in 596 donor blood samples in some towns of Ukraine (Dnepropetrovsk, Kharkov, Odessa, Kiev, Uzhgorod, Zhitomir) are presented. Three normal Hp types (Hp1-1, Hp2-1 and Hp2-2) have been found. The reliable interpopulation differences in the Hp types frequency were not found. On the whole the Hp types frequency in the type Hp1-1 comprised 12.7%. In the type Hp2-1-48.1% and in the type Hp2-2-36.5%. The frequency of the gene Hp1 is 0.38. The frequency of the Hp types and of the gene Hpl in Ukraine is similar to that in population of Eastern Europe and European Part of Russia.     

Line balancing in a just-in-time production environment: balancing multiple U-lines

The introduction of multiple, independent production lines has helped many firms to increase their production flexibility, provide for redundancy when equipment breaks down, reduce idle time and labor costs, and achieve many other benefits. This paper introduces and formalizes the multiple U-line balancing problem. Optimal solution methodologies are provided for Type I (minimize the number of stations for a given cycle time), Type II (minimize the cycle time for a given number of stations), and cost-minimization line-balancing problems. A branch-and-bound algorithm is also developed for the situation in which equipment requirements are dependent on the line configuration and the task assignment to stations. Computational results indicate that the greatest benefit of exploiting multiple lines occurs for smaller cycle-time problems that require higher output.     

Object-oriented query language access to relational databases: A semantic framework for query translation

This research investigates and approach to query processing in a multidatabase system that uses an objectoriented model to capture the semantics of other data models. The object-oriented model is used to construct a global schema, defining an integrated view of the different schemas in the environment. The model is also used as a self-describing model to build a meta-database for storing information about the global schema. A unique aspect of this work is that the object-oriented model is used to describe the different data models of the multidatabase environment, thereby extending the meta database with semantic information about the local schemas. With the global and local schemas all represented in an object-oriented form, structural mappings between the global schema and each local schema are then easily supported. An object algebra then provides a query language for expressing global queries, using the structural mappings to translate object algebra queries into SQL queries over local relational schema. The advantage of using an object algebra is that the object-oriented database can be viewed as a blackboard for temporary storage of local data and for establishing relationships between different databases. The object algebra can be used to directly retrieve temporarily-stored data from the object-oriented database or to transparently retrieve data from local sources using the translation process described in this paper.     

Antimicrobial activity of dogwood fruits (Cornus drummondii) from winter food caches of eastern woodrats (Neotoma floridana)

Post-harvest loss of resources to microbial competitors affects a number of species of animals, and many of them have evolved behaviors that reduce the likelihood of such loss. We previously described the inhibition ofBacillus psychrophilus by dogwood fruits (Cornus drummondii), which can comprise a significant portion of the winter food cache of the eastern woodrat (Neotoma floridana). The present study is a further investigation of the ability of dogwood fruits to inhibit growth ofB. psychrophilus. Additionally, we tested the antimicrobial activity of dogwood fruits onEscherichia coli andStaphlococcus aureus. Results of our study indicate that fresh fruits inhibit the growth ofB. psychrophilus andS. aureus but notE. coli. However, fruits taken from woodrat dens after four and six months storage inhibited growth of all three species of bacteria. Further, the strength of inhibition increased over the test period. We suggest the presence of an inhibitor allows woodrats to compete effectively for a valuable and limited food resource.     

Recruitment strategies in the women's health trial: feasibility study in minority populations. WHT:FSMP Investigators Group. Women's Health Trial:Feasibility Study in Minority Populations

The Women's Health Trial:Feasibility Study in Minority Populations (WHT:FSMP) examined the feasibility of recruiting postmenopausal women from a broad range of racial and socioeconomic backgrounds into a primary prevention trial requiring marked reductions in dietary fat. Postmenopausal women aged 50-79 yr who had no history of cardiovascular disease or cancer and who consumed 36% or more total energy from fat qualified to participate. We randomized the women into dietary intervention (60%) or control (40%) groups; we aimed to randomize 750 women in 18 months in each of the three clinical centers. All centers achieved goals for randomization based on ethnicity, and two centers exceeded overall recruitment goals. The greatest source of randomized participants was mass mailing, followed by items in the media, referrals, and community outreach. Recruitment yields were generally similar for the ethnic groups but lower for less-educated participants. The experience of WHT:FSMP indicates that postmenopausal women from the African-American, Hispanic, and non-Hispanic white communities can be recruited into dietary intervention studies for the prevention of disease.     

Microwave surface resistance of epitaxial YBa2Cu3O7 thin films at 18.7 GHz measured by a dielectric resonator technique

We used a dielectric resonator technique for highly sensitive measurements of the temperature dependence of the microwave surface resistanceR _s of 1×1 cm² superconducting films at 18.7 GHz. It consists of a sapphire disc positioned on the film under investigation within a copper cavity which is acting as a radiation shield. In the TE₀₁ oscillation mode the highly reproducible quality factor of about 10⁵ results in a sensitivity of ±50 forR _s measurements. The temperature dependence ofR _s can be measured up to values as high as 1 . We have investigated several YBa₂Cu₃O₇ thin films prepared by high oxygen pressure d.c. sputtering on LaAlO₃ and NdGaO₃. Our best films exhibit a pronounced nonlinear behavior of the d.c. resistivity(T) with(300K)/(100K) values of about 3.7. Those films show, besides the initial fall-off just belowT _c , a further strong decrease ofR _s at low temperatures. This was observed both at 18.7 GHz and 87 GHz, as measured by a conventional cavity end plate replacement technique. ForTT_c/2 these films exhibit an exp (–T _c/T) dependence ofR _s with-values around 0.4. These observations may be explained by a superconducting energy gap with 2/kT _c0.8 for charge carriers localized in the CuO chains for YBa₂Cu₃O₇.