208 research outputs found
Prediction of heat release effects on a mixing layer
A fully second-order closure model for turbulent reacting flows is suggested based on Favre statistics. For diffusion flames the local thermodynamic state is related to single conserved scalar. The properties of pressure fluctuations are analyzed for turbulent flows with fluctuating density. Closure models for pressure correlations are discussed and modeled transport equations for Reynolds stresses, turbulent kinetic energy dissipation, density-velocity correlations, scalar moments and dissipation are presented and solved, together with the mean equations for momentum and mixture fraction. Solutions of these equations are compared with the experimental data for high heat release free mixing layers of fluorine and hydrogen in a nitrogen diluent
Electrical transport and ferromagnetism in Ga1-xMnxAs synthesized by ion implantation and pulsed-laser melting
We present a detailed investigation of the magnetic and magnetotransport
properties of thin films of ferromagnetic Ga1-xMnxAs synthesized using ion
implantation and pulsed-laser melting (II-PLM). The field and
temperature-dependent magnetization, magnetic anisotropy, temperature-dependent
resistivity, magnetoresistance, and Hall effect of II-PLM Ga1-xMnxAs films have
all of the characteristic signatures of the strong p-d interaction of holes and
Mn ions observed in the dilute hole-mediated ferromagnetic phase. The
ferromagnetic and electrical transport properties of II-PLM films correspond to
the peak substitutional Mn concentration meaning that the non-uniform Mn depth
distribution is unimportant in determining the film properties. Good
quantitative agreement is found with films grown by low temperature molecular
beam epitaxy (LT-MBE) and having the similar substitutional Mn_Ga composition.
Additionally, we demonstrate that II-PLM Ga1-xMnxAs films are free from
interstitial Mn_I because of the high temperature processing. At high Mn
implantation doses the kinetics of solute redistribution during solidification
alone determine the maximum resulting Mn_Ga concentration. Uniaxial anisotropy
between in-plane [-110]and [110] directions is present in II-PLM Ga1-xMnxAs
giving evidence for this being an intrinsic property of the carrier-mediated
ferromagnetic phase
An Experimental and Numerical Study on Glass Frit Wafer-to-Wafer Bonding
A thermo-mechanical wafer-to-wafer bonding process is studied through experiments on the glass frit material and thermo-mechanical numerical simulations to evaluate the effect of the residual stresses on the wafer warpage. To experimentally characterize the material, confocal laser profilometry and scanning electron microscopy for surface observation, energy dispersive X-ray spectroscopy for microstructural investigation, and nanoindentation and die shear tests for the evaluation of mechanical properties are used. An average effective Young’s modulus of 86.5 ± 9.5 GPa, a Poisson’s ratio of 0.19 ± 0.02, and a hardness of 5.26 ± 0.8 GPa were measured through nanoindentation for the glass frit material. The lowest nominal shear strength ranged 1.13 ÷ 1.58 MPa in the strain rate interval to 0.33 ÷ 4.99 × 10 (Formula presented.) s (Formula presented.). To validate the thermo-mechanical model, numerical results are compared with experimental measurements of the out-of-plane displacements at the wafer surface (i.e., warpage), showing acceptable agreement
How Transmembrane Inner Ear (TMIE) plays role in the auditory system: A mystery to us
Different cellular mechanisms contribute to the hearing sense, so it is obvious that any disruption in such processes leads to hearing impairment that greatly influences the global economy and quality of life of the patients and their relatives. In the past two decades, transmembrane inner ear (TMIE) protein has received a great deal of research interest because its impairments cause hereditary deafness in humans. This evolutionarily conserved membrane protein contributes to a fundamental complex that plays role in the maintenance and function of the sensory hair cells. Although the critical roles of the TMIE in mechanoelectrical transduction or hearing procedures have been discussed, there are little to no review papers summarizing the roles of the TMIE in the auditory system. In order to fill this gap, herein, we discuss the important roles of this protein in the auditory system including its role in mechanotransduction, olivocochlear synapse, morphology and different signalling pathways; we also review the genotype-phenotype correlation that can per se show the possible roles of this protein in the auditory system. © 2021 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd
An investigation of the effect of powder flowability on the powder spreading in additive manufacturing
Identification of the most reliable method to characterise powder flow behaviour in correlation with the conditions of powder spreading in additive manufacturing (AM) is still challenging. In this study, a number of standard and advanced flowability techniques were used to characterise the flowability of two grades of Ti6Al4V powder (gas atomized, GA, and hydride-dehydride, HDH) used for the powder bed fusion (PBF) based AM. In parallel, the powder spreading behaviour was characterised using an in-house spreading rig. It is found that GA powder has better spreading behaviour than HDH, owing to its better flowability due to the regular particle shapes. However, none of the flow test techniques investigated in this paper can offer a correlation between the dynamic powder flow and powder spreadability at varying speeds. The study in this work has revealed the shortcomings in correlating the flowability of powder and their spreadability under real process conditions
Ferromagnetism in Ga1-xMnxP: evidence for inter-Mn exchange mediated by localized holes within a detached impurity band
We demonstrate that in ferromagnetic Ga1-xMnxP exchange is mediated by holes
localized in a Mn-derived band. For x<0.06, infrared absorption and
photoconductivity spectra indicate the presence of a Mn impurity band which is
not merged with the valence band. At temperatures above TC (<65 K) electrical
transport is dominated by excitation across this energy gap while nearest
neighbor hopping dominates below TC. Magnetization measurements reveal a moment
of 3.5 Bohr magnetons per substitutional Mn, while the large anomalous Hall
signal unambiguously demonstrates that the ferromagnetism is carrier-mediated.Comment: Equation 1 correcte
Mn L3,2 X-ray Absorption Spectroscopy And Magnetic Circular Dichroism In Ferromagnetic (Ga,Mn)P
We have measured the X-ray absorption (XAS) and X-ray magnetic circular
dichroism (XMCD) at the Mn L3,2 edges in ferromagnetic Ga1-xMnxP films for
0.018<x<0.042. Large XMCD asymmetries at the L3 edge indicate significant
spin-polarization of the density of states at the Fermi energy. The spectral
shapes of the XAS and XMCD are nearly identical with those for Ga1-xMnxAs
indicating that the hybridization of Mn d states and anion p states is similar
in the two materials. Finally, compensation with sulfur donors not only lowers
the ferromagnetic Curie temperature but also reduces the spin polarization of
the hole states.Comment: 2 pages, 1 figure; To appear in the Proceedings of the 28th
International Conference on the Physics of Semiconductors (ICPS-28, Vienna,
Austria, July 24-28, 2006
Biphasic insulin Aspart 30 vs. NPH plus regular human insulin in type 2 diabetes patients; a cost-effectiveness study
Background: The aim of this study was to compare the efficacy, safety, costs, and cost-effectiveness of biphasic insulin aspart 30 (BIAsp 30) with NPH plus regular human insulin (NPH/Reg) in patients with type 2 diabetes mellitus (T2DM). Methods: It was a Single-center, parallel-group, randomized, clinical trial (Trial Registration: NCT01889095). One hundred and seventy four T2DM patients with poorly controlled diabetes (HbA1c � 8 (63.9 mmol/mol)) were randomly assigned to trial arms (BIAsp 30 and NPH/Reg) and were followed up for 48 weeks. BIAsp 30 was started at an initial dose of 0.2-0.6 IU/Kg in two divided doses and was titrated according to the glycemic status of the patient. Similarly, NPH/Reg insulin was initiated at a dose of 0.2-0.6 IU/Kg with a 2:1 ratio and was subsequently titrated. Level of glycemic control, hypoglycemic events, direct and indirect costs, quality adjusted life year (QALY) and incremental cost-effectiveness ratio have been assessed. Results: HbA1c, Fasting plasma glucose (FPG), and two-hour post-prandial glucose (PPG) were improved in both groups during the study (P < 0.05 for all analyses). Lower frequencies of minor, major, and nocturnal hypoglycemic episodes were observed with BIAsp 30 (P < 0.05). Additionally, BIAsp 30 was associated with less weight gain and also higher QALYs (P < 0.05). Total medical and non-medical costs were significantly lower with BIAsp 30 as compared with NPH/Reg (930.55 ± 81.43 USD vs. 1101.24 ± 165.49 USD, P = 0.004). Moreover, BIAsp 30 showed lower ICER as a dominant alternative. Conclusions: Despite being more expensive, BIAsp 30 offers the same glycemic control as to NPH/Reg dose-dependently and also appears to cause fewer hypoglycemic events and to be more cost-effective in Iranian patients with type 2 diabetes. © 2016 The Author(s)
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