Numerical Prediction of a Large Bubble Behavior in Wall Turbulent Flow

Air lubrication systems for underwater applications have gained great popularity in recent years. Large bubbles, around We ≥ 100, show a large area of drag reduction than a small and microbubble, especially for large scale flow problems such as ship surface. However, it is hard to maintain their shape and prone to deform in a turbulent flow. In order to understand and control the drag reduction mechanism by the large bubble injection, it is necessary to know the behavior of large bubbles in the turbulent boundary layer and their interaction with the skin friction. In this study, a solver “interIsoFoam” for two-phase flow of an open-license software “OpenFOAM” is applied for an LES of turbulent channel flow with a large bubble, the gas-liquid interface of which is directly captured by improved VOF method. In a recent publication [1], we presented the numerical procedure of how to inject the large bubble on turbulent channel flow. The research objectives in this study are investigation on flow change of the horizontal channel flow included large bubble. From this observation, understanding large bubbles characteristic such as the surrounding flow phenomena was observed

Numerical Simulation of Flow in a Fuel-Injector of an Aircraft Engine Combustor Using Building-Cube Method

In this study, we investigate grid dependency on local mesh refinement for the numerical simulation of cold flow in an aircraft engine's fuel-injector. The numerical simulation of fully compressible Navier-Stokes equations is conducted using a hierarchical Cartesian mesh-based solver known as 'CUBE'. Using the results of the high-resolution simulation as the basis, the gird dependency analysis is carried out. In addition, we evaluate the weak scaling of the underlying solver

Fluid-Structure Interaction Analysis for Martian Exploration Parafoil with Deployable Structure by Coupling Library Precice

trigger aerodynamic instability. Although instability has been reported in wind tunnel experiments and flight tests, the detailed mechanism of this possible instability has not been clarified. Therefore, it is necessary to elucidate the detailed instability mechanism by numerical analysis, as it cannot be realized experimentally. In addition, it is necessary to introduce fluid-structure interaction (FSI) analysis for flexible structures using a coupled method. The precise code interaction coupling environment (preCICE) coupling library is a powerful tool for the coupling analysis of fluid and structure solvers.  To evaluate the effect of coupling two physical fields, the analyses of the fluid and structure were conducted separately. The results of the analysis verified that the wing deformed under a fluid force, which indicates the effectiveness of the FSI analysis model developed. A comparison with the single-field analysis demonstrated that the structure-derived frequencies in the FSI analysis appeared in the wing surface deformation and aerodynamic forces. However, the aerodynamic coefficients obtained by the FSI analysis converged to the same values as those obtained by the single fluid analysis, thus indicating that from a macroscopic perspective, structural deformation negligibly influences aerodynamic forces. Therefore, it is necessary to analyze a shape that is closer to the actual machine

CURRENT STATUS ON HIGH PERFORMANCE COMPUTING FOR VEHICLE AERODYNAMICS USING LARGE EDDY SIMULATION

ABSTRACT The world's largest class unsteady turbulence simulations of flow around vehicles were conducted using Large Eddy Simulation (LES) on the Earth Simulator in Japan. The main objective of our study is to investigate the validity of LES, as an alternative to a conventional wind tunnel measurement or the Reynolds Averaged Navier-Stokes method, for the assessment of vehicle £ Address all correspondence to this author

Spatial correlation between submillimetre and Lyman-alpha galaxies in the SSA 22 protocluster

Lyman-alpha emitters are thought to be young, low-mass galaxies with ages of ~10^8 yr. An overdensity of them in one region of the sky (the SSA 22 field) traces out a filamentary structure in the early Universe at a redshift of z = 3.1 (equivalent to 15 per cent of the age of the Universe) and is believed to mark a forming protocluster. Galaxies that are bright at (sub)millimetre wavelengths are undergoing violent episodes of star formation, and there is evidence that they are preferentially associated with high-redshift radio galaxies, so the question of whether they are also associated with the most significant large-scale structure growing at high redshift (as outlined by Lyman-alpha emitters) naturally arises. Here we report an imaging survey of 1,100-um emission in the SSA 22 region. We find an enhancement of submillimetre galaxies near the core of the protocluster, and a large-scale correlation between the submillimetre galaxies and the low-mass Lyman-alpha emitters, suggesting synchronous formation of the two very different types of star-forming galaxy within the same structure at high redshift. These results are in general agreement with our understanding of the formation of cosmic structure.Comment: Published in Nature (7th May 2009 issue). The astro-ph paper includes the main text (10 pages, 2 figures, 1 table) and supplementary material (6 pages, 4 figures, 1 table

The Role of Nephritis-Associated Plasmin Receptor (NAPlr) in Glomerulonephritis Associated with Streptococcal Infection

It is well known that glomerulonephritis can occur after streptococcal infection, which is classically referred to as acute poststreptococcal glomerulonephritis (APSGN). The pathogenic mechanism of APSGN has been described by so-called immune complex theory, which involves glomerular deposition of nephritogenic streptococcal antigen and subsequent formation of immune complexes in situ and/or the deposition of circulating antigen-antibody complexes. However, the exact entity of the causative antigen has remained a matter of debate. We isolated a nephritogenic antigen for APSGN from the cytoplasmic fractions of group A streptococcus (GAS) depending on the affinity for IgG of APSGN patients. The amino acid and the nucleotide sequences of the isolated protein revealed to be highly identical to those of reported plasmin(ogen) receptor of GAS. Thus, we termed this antigen nephritis-associated plasmin receptor (NAPlr). Immunofluorescence staining of the renal biopsy tissues with anti-NAPlr antibody revealed glomerular NAPlr deposition in essentially all patients with early-phase APSGN. Furthermore, glomerular plasmin activity was detected by in situ zymography in the distribution almost identical to NAPlr deposition in renal biopsy tissues of APSGN patients. These data suggest that NAPlr has a direct, nonimmunologic function as a plasmin receptor and may contribute to the pathogenesis of APSGN by maintaining plasmin activity

Studies on Melamine Deribatives (Part III) Acylation of Melamine with Chlorobenzoic Anhydrides.

Chlorobenzoic anhydrides were prepared from corresponding o-,m-,or p-chlorobenzoic acid and acetic anhydride by the ordinary method.o-chlorobenzoic anhydride(mp 79-80℃) was obtained in 91.4 % yield, m-chlorobenzoic anhydride (mp 96.5-7℃),in 92.1 % yield and p-chlorobenzoic anhydride (mp 190-2℃), in almost quantitative yield

Primary placement technique of jejunostomy using the entristar™ skin-level gastrostomy tube in patients with esophageal cancer

<p>Abstract</p> <p>Background</p> <p>We developed a skin-level jejunostomy tube (SLJT) procedure for patients undergoing esophagectomy using a skin-level gastrostomy tube (G-tube) (Entristar™; Tyco Healthcare, Mansfield, Mass), in order to improve their nutrition status and quality of life (QOL). We describe the procedure and the adverse effects of SLJT in patients with esophageal cancer (EC).</p> <p>Methods</p> <p>Over a 24-month period (March 2008 to March 2010), there were 16 patients (mean age: 61.8 years; age range: 49-75 years; 15 men, 1 woman) who had Stage II or III EC. Primary jejunostomy was performed under general anesthesia during esophagectomy. The technical success and the immediate and delayed complications of the procedure were recorded.</p> <p>Jejunostomy techniques</p> <p>SLJT placement using the G-tube (20Fr) was performed 20 cm from the Treitz ligament on the side opposing the jejunal mesenterium. The internal retention bolster was exteriorized through an incision in the abdominal wall. A single purse string suture using a 4-0 absorbable suture was performed. The internal retention bolster was then inserted into the jejunal lumen via the small incision. The intestine adjacent to the tube was anchored to the peritoneum using a single stitch.</p> <p>Results</p> <p>The SLJT was successfully inserted in all 16 patients. No early complications were documented. Follow-up for a median of 107 days (range, 26-320 days) revealed leakage to the skin in four patients, including superficial wound infections in two patients. There were no cases of obstruction of the tube or procedure-related death.</p> <p>Conclusions</p> <p>This SLJT placement technique using the G-tube is a safe procedure in patients with EC and allows the creation of a long-term feeding jejunostomy.</p

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (J-SSCG 2016)

Background and purposeThe Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (J-SSCG 2016), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in February 2017 and published in the Journal of JSICM, [2017; Volume 24 (supplement 2)] https://doi.org/10.3918/jsicm.24S0001 and Journal of Japanese Association for Acute Medicine [2017; Volume 28, (supplement 1)] http://onlinelibrary.wiley.com/doi/10.1002/jja2.2017.28.issue-S1/issuetoc.This abridged English edition of the J-SSCG 2016 was produced with permission from the Japanese Association of Acute Medicine and the Japanese Society for Intensive Care Medicine.MethodsMembers of the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine were selected and organized into 19 committee members and 52 working group members. The guidelines were prepared in accordance with the Medical Information Network Distribution Service (Minds) creation procedures. The Academic Guidelines Promotion Team was organized to oversee and provide academic support to the respective activities allocated to each Guideline Creation Team. To improve quality assurance and workflow transparency, a mutual peer review system was established, and discussions within each team were open to the public. Public comments were collected once after the initial formulation of a clinical question (CQ) and twice during the review of the final draft. Recommendations were determined to have been adopted after obtaining support from a two-thirds (> 66.6%) majority vote of each of the 19 committee members.ResultsA total of 87 CQs were selected among 19 clinical areas, including pediatric topics and several other important areas not covered in the first edition of the Japanese guidelines (J-SSCG 2012). The approval rate obtained through committee voting, in addition to ratings of the strengths of the recommendation, and its supporting evidence were also added to each recommendation statement. We conducted meta-analyses for 29 CQs. Thirty-seven CQs contained recommendations in the form of an expert consensus due to insufficient evidence. No recommendations were provided for five CQs.ConclusionsBased on the evidence gathered, we were able to formulate Japanese-specific clinical practice guidelines that are tailored to the Japanese context in a highly transparent manner. These guidelines can easily be used not only by specialists, but also by non-specialists, general clinicians, nurses, pharmacists, clinical engineers, and other healthcare professionals