Direct calorimetric measurements of isothermal entropy change on single crystal W-type hexaferrites at the spin reorientation transition

We report on the magnetic field induced isothermal entropy change, \Delta s(Ha, T), of W-type ferrite with CoZn substitution. Entropy measurements are performed by direct calorimetry. Single crystals of the composition BaCo$_0.62$Zn$_1.38$Fe$_16$O$_27$, prepared by the flux method, are measured at different fixed temperatures under an applied field perpendicular and parallel to the c axis. At 296 K one deduces a value of K$_1$ = 8.7 \times 10^{4} J m$^-3$ for the first anisotropy constant, which is in good agreement with the literature. The spin reorientation transition temperature is estimated to take place between 200 and 220 K

ZB−L′Z^{\prime}_{B-L} phenomenology at LHC

We study the $Z^\prime$ phenomenology for two extensions of the Electroweak Standard Model (SM) which have an extra $U(1)_{B-L}$ gauge factor. We show the capabilities of the LHC in distinguishing the signals coming from these two extensions and both of them from the Standard Model background. In order to compare the behavior of these $B-L$ models we consider the reaction $p + p\longrightarrow \mu^+ + \mu^- + X$ and compute some observables as the total cross sections, number of events, forward-backward asymmetry, final particle distributions like rapidity, transverse momentum, and dimuon invariant mass, for two LHC regimes: $\sqrt{s}\,({\cal L})=7$ TeV ($1\, \textrm{fb}^{-1}$) and $14$ TeV ($100\, \textrm{fb}^{-1}$) for $M_{Z^{\prime}}$ = 1000 GeV and 1500 GeV. We show that by using appropriate kinematic cuts some of the observables considered here are able to extract different properties of the $Z^\prime$ boson, and hence providing information about to which $B-L$ model it belongs to.Comment: 21 pages, 17 figures, 4 table

A kinetic study on the effect of hyperbaric storage on the development of Maillard reaction in glucose-glycine model systems

The effect of pressure (0.1, 15, 50 and 100 MPa) and temperature (43, 53, 63 °C) on the formation rate (k) of Maillard α-dicarbonyls (absorbance at 294) and melanoidins (absorbance at 420 nm), was studied during hyperbaric storage (HS) of glucose-glycine model solutions (pH 6). While increasing storage temperature increased k values according to the Arrhenius equation (Ea ~ 85 kJ mol−1), increasing pressure decreased reaction rates as predicted by the Eyring model (Va ~ 11 mL mol−1). Pressure did not affect reaction temperature sensitivity, indicating no significant mechanism changes under hyperbaric conditions. A combined model predicting the effect of concomitant changes of temperature and pressure on Maillard reaction rate was implemented and validated within and outside (20–25 °C, 20–200 MPa) its building range. Results indicate HS to limit Maillard browning in food, with possible practical applications, and the potential to develop predictive models based on temperature-accelerated HS trials. Industrial relevance: The capability of hyperbaric storage to impair Maillard reaction rate extends the scope of this multi-tasking technology to the prevention of color alterations due to non-enzymatic browning. The latter is expected to be of industrial relevance in the case of perishable foods affected by this phenomenon, such as thermally-treated milk. In these matrices, the technology could concomitantly guarantee microbiological safety, protein functionalization, and Maillard browning impairment

Effect of different diets on the development, mortality, survival, food uptake and fecundity of Tupiocoris cucurbitaceus (Hemiptera: Miridae)

Several Miridae (Hemiptera) species have been identified as useful predators for biological control of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). There is interest in determining the effects of different diets on Tupiocoris cucurbitaceus (Spinola) (Hemiptera: Miridae) in order to facilitate their breeding and use in biological control. Given that mirids can be both phytophagous and zoophytophagous, the developmental time, mortality, survival, feeding and fecundity of this species on tomato and tobacco leaves with and without the addition of T. vaporariorum or Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs were studied. To determine embryonic duration, T. cucurbitaceus was allowed to oviposit on tobacco plants for 24 h at 26 °C, 83% RH and a photoperiod of 16:8 h L:D. The time of onset of the first instar nymphs was recorded. Subsequently, these nymphs fed on different diets on 9 cm × 1.5 cm plates under the same environmental conditions. Results showed that diet influences the duration of development in T. cucurbitaceus, with nymphal stadia being shorter and the adult stadium being longer when fed prey than when not fed prey. With the addition of prey, nymphal mortality was generally lower and adult survival was higher. The high consumption of T. vaporariorum eggs by T. cucurbitaceus suggests the need for subsequent studies on the latter for inclusion of this species in biological control programs in greenhouses

Instability of the expression of morphological and phenological descriptors to environmental variation in white oat.

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Autopsy examination in sudden cardiac death: a current perspective on behalf of the Association for European Cardiovascular Pathology.

In sudden cardiac death, an autopsy is an essential step in establishing a diagnosis of inherited cardiac disease and identifying families that require cardiac screening. To evaluate aspects of post-mortem practice in Europe, a questionnaire was designed and circulated to both clinical and forensic pathologists. There was a 48% response rate and information was obtained from 17 countries. The results showed a wide variety in the management of sudden cardiac death, with a general tendency towards a lack of thorough investigation. In up to 40% of cases, autopsies were not performed in subjects less than 50 years who may have died from cardiac disease. Reasons for this were lack of finance and lack of interest from police, legal authorities, and doctors. Only 50% of pathologists seem to follow a standard protocol for autopsy examination, apparently due to lack of expertise and/or training. When autopsies were performed, histology and toxicology were almost always taken, genetic studies were generally available and retention of the heart for specialist study was usually permitted. Our results suggest that although the standard of practice is appropriate in many centres, many more cases should have autopsies, especially in sudden deaths in subjects less than 50 years

Bifurcation Boundary Conditions for Switching DC-DC Converters Under Constant On-Time Control

Sampled-data analysis and harmonic balance analysis are applied to analyze switching DC-DC converters under constant on-time control. Design-oriented boundary conditions for the period-doubling bifurcation and the saddle-node bifurcation are derived. The required ramp slope to avoid the bifurcations and the assigned pole locations associated with the ramp are also derived. The derived boundary conditions are more general and accurate than those recently obtained. Those recently obtained boundary conditions become special cases under the general modeling approach presented in this paper. Different analyses give different perspectives on the system dynamics and complement each other. Under the sampled-data analysis, the boundary conditions are expressed in terms of signal slopes and the ramp slope. Under the harmonic balance analysis, the boundary conditions are expressed in terms of signal harmonics. The derived boundary conditions are useful for a designer to design a converter to avoid the occurrence of the period-doubling bifurcation and the saddle-node bifurcation.Comment: Submitted to International Journal of Circuit Theory and Applications on August 10, 2011; Manuscript ID: CTA-11-016