Influence of particle size and structure of ZrO2 on microstructure development and dielectric constant of PbZr0.5Ti0.5O3

The synthesis of PbZr0.5Ti0.5O3 ceramics from the raw materials was reinvestigated in order to find relations in the characterizations for the products in various stages of the preparation procedure. Techniques used were particle size measurements, X-ray powder diffractometry, density and dielectric constant measurements and scanning electron microscopy. The results show, that the particle size and structure of ZrO2 determine the inhomogeneity, expressed as xt/xr, of the calcination product. An inhomogeneous calcination product sintered at relatively low temperatures results in an inhomogeneous ceramic of low density. Using high sintering temperatures and long periods of time an inhomogeneous calcination product converts into a dense (>97%) and homogeneous ceramic

Effect of acupressure on cervical ripening

Background: Cervical ripening is one of the main stages of initiation labor. Acupressure in Chinese medicine is considered as an invasive technique, which through reliving oxytocin ripens the cervix. Acupoint Sanyinjiao (SP6) was selected in this study because it is the acupoint selected in gynecology and it is easy for women to locate and apply pressure without medical assistance. Objectives: The aim of this study was to determine the effect of acupressure on cervical ripening. Patients and Methods: In this randomized clinical trial, 150 primigravida with term pregnancy who had referred to Deziani hospital in Gorgan were chosen and divided to three groups: in the first group acupressure was done by the researcher while in the second groups this was performed by the mother her self, and the third group served as a control and only received routine care. For both intervention groups the pressure was applied on Sp6 for about 20 minutes during one to five days. Elements were checked from cervical ripening at 48 and 96 hours after intervention and at the time of hospitalization. The tools for gathering information included demographic characteristics and midwifery history questionnaire, daily records and follow up forms. Content validity was used for validity of tools. Reliability of the observation check-list and physical examination was confirmed by inter-rater scores (inter observer), and daily records by test-re-test. Data was analyzed by analysis of variance (ANOVA), Kruskal-Wallis and Chi-squared tests (P ≤ 0.05). Results: There was a significant difference between mothers’ educations in the three groups. Most of the mothers (59.5%) in the researcher-performed acupressure group had secondary education. Cervical ripening was significantly different between the three groups after 48 hours (P ≤ 0.05), yet there was no significant difference after 96 hours and at the time of admission. Mean Bishop score was enhanced after 48 hours in the researcher-performed acupressure group (P ≤ 0.021) and the self-performed acupressure group (P ≤ 0.007) in comparison to the control group. Conclusions: The results showed that acupressure is a safe technique and leads to cervical ripening. Thus, regarding the desired results that were achieved when mothers applied acupressure themselves, it could be suggested that it is beneficial for mothers to be trained to apply this method at home. © 2015, Iranian Red Crescent Medical Journal

Urinary felinine excretion in intact male cats is increased by dietary cystine

Felinine is a branched-chain sulfur amino acid present in the urine of certain Felidae, including domestic cats. The objective of the present study was to determine if additional cystine and/or dietary N would increase felinine and N-acetylfelinine excretion by intact male cats fed a low-protein (LP) diet. Feeding five adult intact male cats an LP diet (18·8% of metabolisable energy (ME) as protein) v. a high-protein diet (38·6% of ME as protein) resulted in a trend (P¼0·08) for decreased urinary felinine and no change in N-acetylfelinine excretion. In a 23 d study, when the LP diet was supplemented with L-cystine at 9·3 g/kg DM, urinary felinine:creatinine ratio showed a linear two-fold (121 %) increase (P,0·01) from 0·24 (SEM 0·05) to 0·53 (SEM 0·13) after 10 d. Subsequent feeding of the LP diet resulted in a decrease in felinine excretion to base levels. Plasma gglutamylfelinylglycine concentrations were consistent with the excretion of felinine. Supplementation of the LP diet with L-cystine (9·3 g/kg DM), dispensable amino acids and arginine to a second group (n 5) also resulted in a significant (P,0·01) but smaller (þ72 %) increase in the daily felinine:creatinine ratio (0·25 (SEM 0·04) to 0·43 (SEM 0·05)). The degree of felinine N-acetylation within groups was unaffected by dietary addition and withdrawal of amino acids. The results indicate that felinine synthesis is regulated by cystine availability, and that arginine may be physiologically important in decreasing felinine biosynthesis in intact male cats

The electrochemical influence and oxygen exchange properties of mixed conducting electrode materials on solid oxide electrolytes

Electrolyte electrode materials combinations of Er2O3 stabilized Bi2O3 and mixed i.e. both electronic and ionic conducting materials are investigated in order to lower electrode polarization losses and operating temperatures of electrochemical sensors, pumps and SOFC reactors made of them. 18O exchange rates are correlated with exchange current densities

Influence of electrode geometry and NLLS fit analysis of I-V measurements in a three-electrode cell

The analysis of electrode polarisation (I-V) measurements of oxygen electrodes on δ-Bi2O3-based solid electrolytes is complicated by an ohmic polarisation correction which is of the order of the electrode resistance. The analysis can be performed with a NLLS fit technique, which includes this correction resistance, Ru, as adjustable parameter. By an appropriate choice of the electrode geometry the factor Ru can be minimized

Black Hole Production at LHC: String Balls and Black Holes from pp and Lead-lead Collisions

If the fundamental planck scale is near a TeV, then parton collisions with high enough center-of-mass energy should produce black holes. The production rate for such black holes at LHC has been extensively studied for the case of a proton-proton collision. In this paper, we extend this analysis to a lead-lead collision at LHC. We find that the cross section for small black holes which may in principle be produced in such a collision is either enhanced or suppressed, depending upon the black hole mass. For example, for black holes with a mass around 3 TeV we find that the differential black hole production cross section, d\sigma/dM, in a typical lead-lead collision is up to 90 times larger than that for black holes produced in a typical proton-proton collision. We also discuss the cross-sections for `string ball' production in these collisions. For string balls of mass about 1 (2) TeV, we find that the differential production cross section in a typical lead-lead collision may be enhanced by a factor up to 3300 (850) times that of a proton-proton collision at LHC.Comment: Added some discussion, final version to appear in Phys. Rev. D (rapid communications

Wetting of anisotropic sinusoidal surfaces - experimental and numerical study of directional spreading

Directional wettability, i.e. variation of wetting properties depending on the surface orientation, can be achieved by anisotropic surface texturing. A new high precision process can produce homogeneous sinusoidal surfaces (in particular parallel grooves) at the micro-scale, with a nano-scale residual roughness five orders of magnitude smaller than the texture features. Static wetting experiments have shown that this pattern, even with a very small aspect ratio, can induce a strong variation of contact angle depending on the direction of observation. A comparison with numerical simulations (using Surface Evolver software) shows good agreement and could be used to predict the fluid-solid interaction and droplet behaviour on textured surfaces. Two primary mechanisms of directional spreading of water droplets on textured stainless steel surface have been identified. The first one is the mechanical barrier created by the textured surface peaks, this limits spreading in perpendicular direction to the surface anisotropy. The second one is the capillary action inside the sinusoidal grooves accelerating spreading along the grooves. Spreading has been shown to depend strongly on the history of wetting and internal drop dynamics

Bismuth oxide based ceramics with improved electrical and mechanical properties: Part II. Structural and mechanical properties

Coprecipitation as a method of preparation for bismuth oxides based ceramics yields relatively strong and machineable materials in comparison with the solid state reaction. Compositions within the system (1−x)Bi2O3|xEr2O3 containing up to twenty five mole percent of erbium oxide show a slow transition on heating at 900 K from a cubic to a hexagonal (rhombohedral) phase. The resulting hexagonal phase is stable up to 1000 K where it transforms back to the cubic phase. Long term heating at 775 K causes formation of traces of ∝ - bismuth oxide in these samples, but the material itself remains cubic. Compositions containing thirty mole percent of erbium oxide do not show any such changes and hence are suitable for application purposes

A Combinatorial Polynomial Algorithm for the Linear Arrow-Debreu Market

We present the first combinatorial polynomial time algorithm for computing the equilibrium of the Arrow-Debreu market model with linear utilities.Comment: Preliminary version in ICALP 201