Superplastic forming of ceramic insulation

Superplasticity has been demonstrated in many fine-grained structural ceramics and ceramic composites, including yttria-stabilized tetragonal zirconia polycrystal (YTZP), alumina, and Al2O3-reinforced zirconia (Al2O3/YTZ) duplex composites and SiC-reinforced Si3N4. These superplastic ceramics obviously offer the potential benefit of forming net shape or near net shape parts. This could be particularly useful for forming complicated shapes that are difficult to achieve using conventional forming techniques, or require elaborate, subsequent machining. In the present study, we successfully demonstrated the following: (1) superplastic 3Y-TXP and 20 percent Al2O3/YTZ composite have for the first time been successfully deformed into hemispherical caps via a biaxial gas-pressure forming technique; (2) no experimental difficulty was encountered in applying the required gas pressures and temperatures to achieve the results, thus, it is certain that higher rates of deformation than those presented in this study will be possible by using the current test apparatus at higher temperatures and pressures; and (3) an analytical model incorporating material parameters, such as variations during forming in the strain rate sensitivity exponent and grain growth-induced strain hardening, is needed to model accurately and therefore precisely control the biaxial gas-pressure forming of superplastic ceramics. Based on the results of this study, we propose to fabricate zirconia insulation tubes by superplastic extrusion of zirconia polycrystal. This would not only reduce the cost, but also improve the reliability of the tube products

A Multinational Study of Acute and Long‐Term Outcomes of Type 1 Galactosemia Patients Who Carry the S135L (c.404C > T) Variant of GALT

Patients with galactosemia who carry the S135L (c.404C > T) variant of galactose-1-P uridylyltransferase (GALT), documented to encode low-level residual GALT activity, have been under-represented in most prior studies of outcomes in Type 1 galactosemia. What is known about the acute and long-term outcomes of these patients, therefore, is based on very limited data. Here, we present a study comparing acute and long-term outcomes of 12 patients homozygous for S135L, 25 patients compound heterozygous for S135L, and 105 patients homozygous for two GALT-null (G) alleles. This is the largest cohort of S135L patients characterized to date. Acute disease following milk exposure in the newborn period was common among patients in all 3 comparison groups in our study, as were long-term complications in the domains of speech, cognition, and motor outcomes. In contrast, while at least 80% of both GALT-null and S135L compound heterozygous girls and women showed evidence of an adverse ovarian outcome, prevalence was only 25% among S135L homozygotes. Further, all young women in this study with even one copy of S135L achieved spontaneous menarche; this is true for only about 33% of women with classic galactosemia. Overall, we observed that while most long-term outcomes trended milder among groups of patients with even one copy of S135L, many individual patients, either homozygous or compound heterozygous for S135L, nonetheless experienced long-term outcomes that were not mild. This was true despite detection by newborn screening and both early and life-long dietary restriction of galactose. This information should empower more evidence-based counseling for galactosemia patients with S135L.info:eu-repo/semantics/publishedVersio

Intrinsic nanoscale inhomogeneity in ordering systems due to elastic-mediated interactions

Phase diagram and pattern formation in two-dimensional Ising model with coupling between order parameter and lattice vibrations is investigated by Monte-Carlo simulations. It is shown that if the coupling is strong enough (or phonons are soft enough) a short-range order exists in disordered phase for a broader temperature interval. Different types of this short-range order (stripe-like, checkboard-like, etc.) depending on the temperature and model parameters are investigated. With further increase of the coupling, a reconstruction of the ground state happens and new ordered phases appear at low enough temperatures.Comment: final version, Europhys. Lett., accepte

The costs of urban sprawl : how municipal service costs are impacted by land area consumption

M.S. (Master of Science

Rapid assessment of the effectiveness of antioxidant active packaging – Study with grape pomace and olive leaf extracts

Natural antioxidants are mixtures of different components with their specific partition and diffusion coefficients and the exact description of the release kinetics into foods is, therefore, complex. For practical application however, the interest should be focused on the antioxidant effect rather than on the single compounds release, i.e., it is an approximation to describe the release of a mixture by treating it as single substance. The evaluation of such approach was subject of this study.Film samples coated with Shellac (Shel) and cellulose nitrate (NC), containing olive leaf extract (OLE) and grape pomace extract (GPE) at different concentrations were put in contact with three food simulants, namely W (water), A (10% ethanol) and D1 (50% ethanol), and the antioxidant capacity was assessed by suitably modified ABTS test.The equilibrium antioxidant capacity increased from W to A and D1 for GPE and OLE: the antioxidant levels attained films containing GPE were 0.272, 0.483 and 0.728. Trolox. mEq/L at 5% concentration, and 0.705, 0.786 and 0.893. Trolox. mEq/L at 10% concentration for W, A and D1 simulants, respectively. The method was also effective at comparing the lacquer retention performances, NC being more effective than the Shel, i.e., it showed a faster release of antioxidant compounds