in the present study, a heterogeneous and homogeneous gas flow dispersion model for simulation and optimization of a large-scale catalytic slurry reactor for the direct synthesis of dimethyl ether (dme) from synthesis gas (syngas) and co2, using a churn-turbulent regime was developed. in the heterogeneous flow model, the gas phase was distributed into two bubble phases including small and large...

one of the main components affecting the ecohydrology is interception or loss of rainfall by plant canopy. interception of reduced effective precipitation and dry areas to prevent soil moisture. low level of abstraction is considered as important factors in managing rangeland resources. in this study, the vegetative form, some broad-leaved plants and plant selection and method of abstraction in...

In the present research, the mixed-mode fracture mechanics analysis in a plate with central hole under tensile loading is considered. It is assumed that a plate containing two symmetrical hole-edge cracks is bonded with two dissimilar planes. The stress intensity factors at the crack tips are calculated. The problem is modeled in Casca software and this model is analyzed with Franc software. Th...

Objective Determine if anatomic dimensions of airway structures are associated with airway obstruction in obstructive sleep apnea (OSA) patients. Methods Twenty-eight subjects with (n = 14) and without (n = 14) OSA as determined by clinical symptoms and sleep studies; volunteer sample. Skeletal and soft tissue dimensions were measured from radiocephalometry and magnetic resonance imaging. The...

Nanocrystal array solar cells based on lead chalcogenide quantum dots (QDs) have recently achieved a high power conversion efficiency of over 8%. The device performance is expected to further increase by using 1-dimensional nanorods (NRs), due to their improved carrier transport over zero-dimensional quantum dots. However, previously reported PbSe NRs have not been used in solar cells mainly be...

An incrementally coupled electrical – thermal – mechanical model is developed to simulate small scale resistance spot welding (SSRSW) using the finite element method. This numerical model is then employed to study the differences between SSRSW and ‘large scale’ resistance spot welding (LSRSW). The variations in contact area, current distribution, and temperature profile at the workpiece/workpie...

Let G be a unit-distance graph in R2. For each unit-distance representation of G in R2, there is a smallest circumscribing circle. The infimum of the diameters of these circles, taken over all unit-distance representations of G, is called the span of G. On the other hand, the supremum of the diameters of all such circles is called the extent of G. We show that the ratio of the extent to the dia...

Porous materials are widely employed as supports in the immobilisation of enzymes. Traditionally macroporous materials with pore diameters >50 nm were believed to be the most suitable support material, ensuring no spatial restrictions upon enzyme molecules entering such large pores. In recent years however, there has been growing emphasis in the use of mesoporous supports with pore diameters ra...

Background and Aim: Screw loosening is a common problem with both screw-retained and cemented implant restorations. It is assumed that the abutment diameter affects detorque value and screw loosening. We aimed to determine the effect of two different abutment diameters on detorque value using cyclic loading and thermocycling. Materials and Methods: This in-vitro experimental study was conducte...

OBJECTIVE To investigate the differences between tumor sizes measured by preoperative computed tomography (CT) imaging and pathologic examination of surgical specimens in Chinese patients who received extirpative surgery for renal tumors. METHODS From September 2008 to September 2010, 204 patients with renal tumors treated in the Renji Hospital were enrolled in this study, and their clinicopa...