Decomposition of the Sum of Cubes, the Sum Raised to the Power of Four and Codeviance

The purpose of this paper is to achieve decomposition formulas of sums regarding deviation cubes, the sum of deviation raised to the power of four and codeviance, because they allow to evaluate the contribution of different components of the above three absolute measures regarding asymmetry, disnormality and concordance. We have obtained more significant formulas that are valid only for two groups, in addition to the formulas valid for r groups, and we have prepared an example to emphasize how useful those formulas were

Double diffusion in a rectangular duct using metals or oxides suspended in a viscous fluid

In this study, double diffusive free convection of nanofluid within a confined rectangular duct is investigated numerically. The momentum and energy equations are placed in the form of difference equations and solved numerically. The left wall conditions for the concentration and temperature are lesser than those of the right wall and the upper and lower walls are insulated. Different nanofluids are considered such as mixtures with copper, diamond, silicon oxide and titanium oxide, suspended in water. Brinkman and Maxwell models are used to characterize the nanofluid. Tiwari and Das model is opted to define the nanofluid behavior. The simulations are conducted using different nanoparticles, thermal Grashof number 1 ≤ GrT ≤ 20, solute Grashof number 1 ≤ GrC ≤ 15, solid volume fraction 0 ≤ Φ ≤ 0.05, Dufour number 0 ≤ Df ≤ 1, Brinkman number 0 ≤ Br ≤ 2, and Soret number 0 ≤ Sr ≤ 5. Additionally, behavior of volumetric flow strength, skin friction, heat transport intensity and Sherwood number is also examined. The thermal Grashof number, Brinkman number, Dufour, Soret and Schmidt parameters accelerate the velocity and temperature and dwindle the concentration whereas the reversal effect was obtained for the solid volume fraction. The concentration Grashof number diminishes the velocity and temperature and intensifies the concentration. The silver nanoparticles produce the highest velocity whereas diamond nanoparticles cause the lowest velocity and temperature. The maximum temperature is attained with silicon oxide

Centre selection for clinical trials and the generalisability of results: a mixed methods study.

BACKGROUND: The rationale for centre selection in randomised controlled trials (RCTs) is often unclear but may have important implications for the generalisability of trial results. The aims of this study were to evaluate the factors which currently influence centre selection in RCTs and consider how generalisability considerations inform current and optimal practice. METHODS AND FINDINGS: Mixed methods approach consisting of a systematic review and meta-summary of centre selection criteria reported in RCT protocols funded by the UK National Institute of Health Research (NIHR) initiated between January 2005-January 2012; and an online survey on the topic of current and optimal centre selection, distributed to professionals in the 48 UK Clinical Trials Units and 10 NIHR Research Design Services. The survey design was informed by the systematic review and by two focus groups conducted with trialists at the Birmingham Centre for Clinical Trials. 129 trial protocols were included in the systematic review, with a total target sample size in excess of 317,000 participants. The meta-summary identified 53 unique centre selection criteria. 78 protocols (60%) provided at least one criterion for centre selection, but only 31 (24%) protocols explicitly acknowledged generalisability. This is consistent with the survey findings (n = 70), where less than a third of participants reported generalisability as a key driver of centre selection in current practice. This contrasts with trialists' views on optimal practice, where generalisability in terms of clinical practice, population characteristics and economic results were prime considerations for 60% (n = 42), 57% (n = 40) and 46% (n = 32) of respondents, respectively. CONCLUSIONS: Centres are rarely enrolled in RCTs with an explicit view to external validity, although trialists acknowledge that incorporating generalisability in centre selection should ideally be more prominent. There is a need to operationalize 'generalisability' and incorporate it at the design stage of RCTs so that results are readily transferable to 'real world' practice

Heat transfer of chemically reacting mixed convection fluid using convective surface condition: Non-Darcy model

This work reports the study of mixed convection of permeable fluid with Robin conditions in the vertical channel including the effects of chemical reactions. The fluid transport is designed by the Darcy-Forchheimer-Brinkman model. The series method is adopted for approximate solutions for governing equations considering the Brinkman number as the perturbation characteristic whose outcomes correspond to magnitudes of Brinkman number less than one. Adopting a numerical scheme followed by fourth order Runge–Kutta algorithm with shooting method, the solutions for bigger magnitudes of the Brinkman number are obtained. The present results for limiting cases are compared with the literature and good agreement is seen. For various values of thermal and mass Grashof numbers, porous parameter, inertial parameter, Darcy number and first order chemical reaction the problem is resolved for the same and distant Biot numbers reflecting the border temperatures symmetric and asymmetric. Finally, the outcomes are tabulated for wall friction parameters, Nusselt and Sherwood numbers for innovated parameters. It is noticed that enhancing buoyancy and dissipations, thermal Grashof number helps to improve the flow rate for all values of Biot number. The Schmidt and Soret parameters can improve concentration patterns. Nusselt number can be improved with thermal Grashof number and Brinkman number and it is dropped with inertia and porous parameters. The solutions have a very good agreement with Zanchini data without mass Grashof number

Towards Micromechanical Sensors with (La,Sr)MnO3 Epitaxial Films☆

Abstract The rich spectrum of functionalities exhibited by oxide thin films is an appealing feature for the development of micro and nanomechanical devices [1,2] . MEMS made of heterostructures of crystalline oxide materials having targeted physical properties may be applied as sensors having different integrated functionalities. In this work, we explore the feasibility of manganite thin film based epitaxial MEMS for magnetic micromechanical sensing. We investigate the electromechanical properties of LSMO freestanding structures for future applications in the field of micromechanical magnetic sensors

Exciton states in monolayer MoSe2 and MoTe2 probed by upconversion spectroscopy

Transitions metal dichalcogenides (TMDs) are direct semiconductors in the atomic monolayer (ML) limit with fascinating optical and spin-valley properties. The strong optical absorption of up to 20 % for a single ML is governed by excitons, electron-hole pairs bound by Coulomb attraction. Excited exciton states in MoSe$_2$ and MoTe$_2$ monolayers have so far been elusive due to their low oscillator strength and strong inhomogeneous broadening. Here we show that encapsulation in hexagonal boron nitride results in emission line width of the A:1$s$ exciton below 1.5 meV and 3 meV in our MoSe$_2$ and MoTe$_2$ monolayer samples, respectively. This allows us to investigate the excited exciton states by photoluminescence upconversion spectroscopy for both monolayer materials. The excitation laser is tuned into resonance with the A:1$s$ transition and we observe emission of excited exciton states up to 200 meV above the laser energy. We demonstrate bias control of the efficiency of this non-linear optical process. At the origin of upconversion our model calculations suggest an exciton-exciton (Auger) scattering mechanism specific to TMD MLs involving an excited conduction band thus generating high energy excitons with small wave-vectors. The optical transitions are further investigated by white light reflectivity, photoluminescence excitation and resonant Raman scattering confirming their origin as excited excitonic states in monolayer thin semiconductors.Comment: 14 pages, 7 figures, main text and appendi

Concentrations of free radicals and beta-endorphins in repeat breeder cows

Repeat breeding (RB) is one of the major problems that affect the reproductive efficiency and economy of milk production in dairy animals. So far, the etiopathogenesis of this pathology has not been defined completely. Stress has been hypothesized to be a cause of impaired reproductive efficiency. Stress may cause an overproduction of beta-endorphins and free radicals; in particular, reactive oxygen species (ROS). The aim of this work is to determine the concentrations of these substances in RB cows and to evaluate the correlation with the serum level of progesterone. The study was performed on 60 dairy cows: 26 RB and 34 control cows. Blood samples were collected on day 12 and day 16, after artificial insemination (AI) in all subjects, in order to assess the concentrations of progesterone, free radicals and beta-endorphins. The stressors, free radicals and beta-endorphins, that we considered, were higher in repeat breeders (day 12, 93.32(±1.91) UCarr and 0.50(±0.03) ng/ml; day 16, 94.42(±1.91) UCarr and 0.61(±0.03) ng/ml), with a lower level of progesterone, which probably is responsible for failure to conceive. The stress factors (free radicals and beta-endorphins) may actually enhance each other and induce an inhibition of progesterone synthesis in repeat breeders

Is it possible to compare inhibitory and excitatory intracortical circuits in face and hand primary motor cortex?

Face muscles are important in a variety of different functions, such as feeding, speech and communication of non-verbal affective states, which require quite different patterns of activity from those of a typical hand muscle. We ask whether there are differences in their neurophysiological control that might reflect this. Fifteen healthy individuals were studied. Standard single- and paired-pulse transcranial magnetic stimulation (TMS) methods were used to compare intracortical inhibitory (short interval intracortical inhibition (SICI); cortical silent period (CSP)) and excitatory circuitries (short interval intracortical facilitation (SICF)) in two typical muscles, the depressor anguli oris (DAO), a face muscle, and the first dorsal interosseous (FDI), a hand muscle. TMS threshold was higher in DAO than in FDI. Over a range of intensities, resting SICF was not different between DAO and FDI, while during muscle activation SICF was stronger in FDI than in DAO (P = 0.012). At rest, SICI was stronger in FDI than in DAO (P = 0.038) but during muscle contraction, SICI was weaker in FDI than in DAO (P = 0.034). We argue that although many of the difference in response to the TMS protocols could result from the difference in thresholds, some, such as the reduction of resting SICI in DAO, may reflect fundamental differences in the physiology of the two muscle groups

A mechanistic investigation of the ruthenium porphyrin catalysed aziridination of olefins by aryl azides

A combination of DFT and kinetic studies suggests a mechanism for olefin aziridination by organic azides catalysed by ruthenium porphyrins