Three Dimensional Compressible Turbulent Flow Computations for a Diffusing S-Duct With/Without Vortex Generators

Numerical investigations on a diffusing S-duct with/without vortex generators and a straight duct with vortex generators are presented. The investigation consists of solving the full three-dimensional unsteady compressible mass averaged Navier-Stokes equations. An implicit finite volume lower-upper time marching code (RPLUS3D) has been employed and modified. A three-dimensional Baldwin-Lomax turbulence model has been modified in conjunction with the flow physics. A model for the analysis of vortex generators in a fully viscous subsonic internal flow is evaluated. A vortical structure for modeling the shed vortex is used as a source term in the computation domain. The injected vortex paths in the straight duct are compared with the analysis by two kinds of prediction models. The flow structure by the vortex generators are investigated along the duct. Computed results of the flow in a circular diffusing S-duct provide an understanding of the flow structure within a typical engine inlet system. These are compared with the experimental wall static-pressure, static- and total-pressure field, and secondary velocity profiles. Additionally, boundary layer thickness, skin friction values, and velocity profiles in wall coordinates are presented. In order to investigate the effect of vortex generators, various vortex strengths are examined in this study. The total-pressure recovery and distortion coefficients are obtained at the exit of the S-duct. The numerical results clearly depict the interaction between the low velocity flow by the flow separation and the injected vortices

Simulation of Flood Propagation Due to Levee Break Using the Cartesian Cut Cell Method

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Primary Segmental Volvulus of Small Intestine: Surgical Perspectives According to Age at Diagnosis

Background: Small intestinal volvulus often occurs with malrotation. However, in some cases, it could develop without any other clinical conditions, and this is called primary segmental volvulus (PSV) of the small intestine. Two types of PSV (early and late neonatal) have been described previously, especially in preterms. Moreover, there were other cases occurring beyond the neonatal period.Methods: The medical records of 14 cases definitively identified as PSV were retrospectively reviewed. The patients were divided into 2 groups according to postnatal age at diagnosis: neonatal group and beyond neonatal group. Then, the 2 groups were compared in terms of clinical features.Results: There were 11 patients in the neonatal group (78.6%) and 3 patients in the beyond neonatal group (21.4%). There were no differences in gestational age, birth weight, and ratio of prematurity. In the neonatal group, the antenatal abnormal sonographic findings were found more frequently and the perforation of the involved segment were relatively common. Meanwhile, the involved segment was confined to the ileum and more commonly associated with mesentery change in the beyond neonatal group. There was no mortality.Conclusion: The 2 clinical types of PSV according to postnatal age at diagnosis show some differences in clinical features. Moreover, PSV should be considered a possible cause of surgical problems beyond the neonatal period

Regulation of Apoptosis during Environmental Skin Tumor Initiation

Skin cancer is more prevalent than any other cancer in the United States. Nonmelanoma skin cancers are the more common forms of skin cancer that affect individuals. The development of squamous cell carcinoma, the second most common type of skin cancer, can be stimulated by exposure of environmental carcinogens, such as chemical toxicants or UVB. It is developed by three distinct stages: initiation, promotion, and progression. During the initiation, the fate of DNA-damaged skin cells is determined by the homeostatic regulation of pro-apoptotic and antiapoptotic signaling pathways. The imbalance or disruption of either signaling will lead to the survival of initiated cells, resulting in the development of skin cancer. In this chapter, we will discuss signaling pathways that regulate apoptosis and the impact of their dysfunction during skin tumor initiation

Regulation of Apoptosis during Environmental Skin Tumor Initiation

Skin cancer is more prevalent than any other cancer in the United States. Nonmelanoma skin cancers are the more common forms of skin cancer that affect individuals. The development of squamous cell carcinoma, the second most common type of skin cancer, can be stimulated by exposure of environmental carcinogens, such as chemical toxicants or UVB. It is developed by three distinct stages: initiation, promotion, and progression. During the initiation, the fate of DNA-damaged skin cells is determined by the homeostatic regulation of pro-apoptotic and antiapoptotic signaling pathways. The imbalance or disruption of either signaling will lead to the survival of initiated cells, resulting in the development of skin cancer. In this chapter, we will discuss signaling pathways that regulate apoptosis and the impact of their dysfunction during skin tumor initiation

Violet-light spontaneous and stimulated emission from ultrathin In-rich InGaN/GaN multiple quantum wells grown by metalorganic chemical vapor deposition

We investigated the spontaneous and stimulated emission properties of violet-light-emitting ultrathin In-rich InGaN/GaN multiple quantum wells (MQWs) with indium content of 60%-70%. The Stokes shift was smaller than that of In-poor InGaN MQWs, and the emission peak position at 3.196 eV was kept constant with increasing pumping power, indicating negligible quantum confined Stark effect in ultrathin In-rich InGaN MQWs despite of high indium content. Optically pumped stimulated emission performed at room temperature was observed at 3.21 eV, the high-energy side of spontaneous emission, when the pumping power density exceeds ???31 kW/ cm2.open6

Two cases of splenic infarction due to torsion of wandering spleen requiring laparoscopic splenectomy in adolescent girls

Wandering spleen is a rare condition in which the spleen is not found in its usual location or presentation. Its vascular pedicle can be twisted easily, and compromised vasculature of spleen. Consequently, it may result in splenic infarction requiring diagnosis and treatment. Here we present 2 cases of splenic infarction due to torsion of wandering spleen in 2 adolescent girls who visited the emergency department presenting with abdominal pain. Prompt computed tomography scan led early diagnosis and successful laparoscopic splenectomy. We also reviewed the literature on this entity briefly