An analysis of turbulent diffusion flame in axisymmetric jet

The kinetic theory of turbulent flow was employed to study the mixing limited combustion of hydrogen in axisymmetric jets. The integro-differential equations in two spatial and three velocity coordinates describing the combustion were reduced to a set of hyperbolic partial differential equations in the two spatial coordinates by a binodal approximation. The MacCormick's finite difference method was then employed for solution. The flame length was longer than that predicted by the flame-sheet analysis, and was found to be in general agreement with a recent experimental result. Increase of the turbulence energy and scale resulted in an enhancement of the combustion rate and, hence, in a shorter flame length. Details of the numerical method as well as of the physical findings are discussed

The Effects of Insider Ownership and Board Composition on Firm Performance in the Restaurant Industry

This study aimed to investigate the relations among insider ownership, board composition, and firm performance in U.S. restaurant firms. The authors divided insider ownership into three categories: the equity ownership held per insider owners, the equity ownership held by nonexecutive (outside) directors, and the equity ownership shared by executive officers. Board composition was represented by board independence, board size, and chief executive officer duality. For data analysis, the authors conducted 319 observations from 31 firms. The authors found that 3 categories of insider ownership and board composition variables differently influence short-term operational profitability and long-term value. Managerial ownership negatively influences short-term profitability, whereas long-term value is affected not only by managerial ownership but also by a balanced dispersion of shares to each owner. Dual chief executive officers do not affect short-term profitability but negatively influence long-term value. The study findings provide more comprehensive understanding of the effect of the corporate governance system on firm performance in the restaurant industry

A Novel Bias Correction Method for Soil Moisture and Ocean Salinity (SMOS) Soil Moisture: Retrieval Ensembles

Bias correction is a very important pre-processing step in satellite data assimilation analysis, as data assimilation itself cannot circumvent satellite biases. We introduce a retrieval algorithm-specific and spatially heterogeneous Instantaneous Field of View (IFOV) bias correction method for Soil Moisture and Ocean Salinity (SMOS) soil moisture. To the best of our knowledge, this is the first paper to present the probabilistic presentation of SMOS soil moisture using retrieval ensembles. We illustrate that retrieval ensembles effectively mitigated the overestimation problem of SMOS soil moisture arising from brightness temperature errors over West Africa in a computationally efficient way (ensemble size: 12, no time-integration). In contrast, the existing method of Cumulative Distribution Function (CDF) matching considerably increased the SMOS biases, due to the limitations of relying on the imperfect reference data. From the validation at two semi-arid sites, Benin (moderately wet and vegetated area) and Niger (dry and sandy bare soils), it was shown that the SMOS errors arising from rain and vegetation attenuation were appropriately corrected by ensemble approaches. In Benin, the Root Mean Square Errors (RMSEs) decreased from 0.1248 m3/m3 for CDF matching to 0.0678 m3/m3 for the proposed ensemble approach. In Niger, the RMSEs decreased from 0.14 m3/m3 for CDF matching to 0.045 m3/m3 for the ensemble approach.open

Modeling of Fuel Vapor Jet Eruption Induced by Local Droplet Heating

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140419/1/6.2014-1017.pd

Nanocomposite hydrogel actuators hybridized with various dimensional nanomaterials for stimuli responsiveness enhancement

Hydrogel actuators, that convert external energy, such as pH, light, heat, magnetic field, and ion strength, into mechanical motion, have been utilized in sensors, artificial muscles, and soft robotics. For a practicality of the hydrogel actuators in a wide range of fields, an establishment of robust mechanical properties and rapid response are required. Several solutions have been proposed, for example, setting porous and anisotropy structures to hydrogels with nanocomposite materials to improve the response speed and deformation efficiency. In this review paper, we focused on hydrogel actuators including various nanocomposite by categorizing the dimensional aspects of additive materials. Moreover, we described the role of diverse additive materials in terms of the improvement of mechanical property and deformation efficiency of the hydrogel actuators. We assumed that this review will provide a beneficial guidance for strategies of developing nanocomposite hydrogel actuators and outlooks for the future research directions.11Ysciescopu

Fluticasone furoate and vilanterol for the treatment of chronic obstructive pulmonary disease

Introduction: Current national and international guidelines for the management of patients with stable chronic obstructive pulmonary disease (COPD) recommend the use of inhaled long-acting bronchodilators, inhaled glucocorticoids and their combinations for maintenance treatment of moderate to severe stable COPD. Areas covered: The role of fluticasone furoate (FF) and vilanterol (VI) once daily combination therapy for the regular treatment of patients with stable COPD is discussed in this review. Expert commentary: The regular treatment of moderate to severe stable COPD with once daily FF/VI combination therapy is effective, as seen in in several large placebo-controlled clinical trials involving many thousands of patients. FF/VI improved lung function, decreased respiratory symptoms and deceased the number of COPD exacerbations, including COPD-related hospitalizations. FF/VI combination therapy has also been approved for this indication in most countries. The use of this combination therapy may significantly decrease the economic costs for some National Health Services

Synthesis and Properties of Fluorinated Polyimides from Rigid and Twisted Bis(Trifluoromethyl)Benzidine for Flexible Electronics

Fluorinated polyimides were prepared from the twisted benzidine monomer containing two trifluoromethyl (CF3) groups on one aromatic ring. The diamine monomer having a rigid and nonplanar structure was polymerized with typical dianhydride monomers including BPDA, BTDA, ODPA, 6-FDA, and PMDA, to obtain the corresponding polyimides. Most polyimides are soluble in organic solvents due to their twisted chain structure and can be solution cast into flexible and tough films. These films have a UV-vis absorption cut-off wavelength at 354–398 nm and a light transparency of 34–90% at a wavelength of 550 nm. They also have tensile strengths of 92–145 MPa and coefficients of thermal expansion (CTE) of 6.8–63.1 ppm/°C. The polymers exhibited high thermal stability with 5% weight loss at temperatures ranging from 535 to 605°C in nitrogen and from 523 to 594°C in air, and high glass temperature (Tg) values in the range of 345–366°C. Interestingly, some of the soluble polyimides showed thermo-responsive behaviors in organic solvents presumably due to the multiple hydrogen bondings with unsymmetrically positioned two CF3 groups along the polymer chains