Fuel stagnation temperature effects on mixing with supersonic combustion flows

An experimental study of the effect of fuel stagnation temperature on mixing in a supersonic hydrogen-air flame is described, The combustor consisted of a constant-area rectangular duct with a centrally located fuel-injection strut that spanned the width. A high-enthalpy stream of air was supplied by a free-piston shock tunnel, and heated hydrogen fuel, supplied by a gun-tunnel, was injected into the freestream as a coflowing planar jet. The freestream total enthalpies were 5.6, 6.5, and 9 MJ/kg, and fuel stagnation temperatures were 300, 450, and 700 K, Raising the fuel stagnation temperature increased the fuel velocity to be near that of the airstream and resulted in a decrease in the mixing rate, Even as the fuel and air velocities became equal, significant mixing still occurred because of a large difference in density, Increasing the freestream enthalpy reduced the difference between the initial air temperature and the adiabatic flame temperature, which in turn reduced the heat addition, and subsequently, the amount of pressure rise in the duct.

Structural characterisation of galactoglucomannan secreted by suspension-cultured cells of Nicotiana plumbaginifolia

Galactoglucomannan (GGM) from cultures of Nicotiana plumbaginifolia has Man:Glc:Gal:Ara:Xyl in 1.0:1.1:1.0:0.1:0.04 ratio. Linkage analysis contained 4- and 4,6-Manp, 4-Glcp, terminal Galp and 2-Galp, small amounts and terminal Arap and terminal Xylp, and similar to 0.03 mol acetyl per mol of glucosyl residue. Treatment with alpha- and beta-D-galactosidases showed that the majority of the side-chains were either single Galp-alpha-(1 --> residues or the disaccharide Galp-beta-(1 --> 2)-Galp-alpha-(1 --> linked to O-6 of the 4-Manp residues of the glucomannan backbone. Analysis of the oligosaccharides generated by endo-(1 --> 4)-beta-mannanase digestion confirmed that the GGM comprises a backbone of predominantly alternating --> 4)-D-Manp-beta-(1 --> and --> Lt)-D-Glcp-beta-(1 --> branched at O-6 of 65% of the 4-Manp residues. The major oligosaccharide identified was D-Glcp-beta-(1 --> 4)-[D-Galp-beta-(1 --> 2)-D-Galp-alpha-(1 --> 6)]-D-Manp-beta-(1 --> 4)-D-Glcp-beta-(I --> 4)-[D-Galp-alpha-(1 --> 6)]-D-Manp-beta-(1 --> (27%), and most of the other oligosaccharides produced in significant quantities were based on this structure. (C) 1997 Elsevier Science Ltd.

Periurethral Suspension Stitch During Robot-Assisted Laparoscopic Radical Prostatectomy: Description of the Technique and Continence Outcomes

Background: Several studies have shown that robot-assisted laparoscopic radical prostatectomy (RALP) is feasible, with favorable complication rates and short hospital times. However, the early recovery of urinary continence remains a challenge to be overcome. Objective: We describe our technique of periurethral retropubic suspension stitch during RALP and report its impact on early recovery of urinary continence. Design, setting, and participants: We analyze prospectively 331 consecutive patients who underwent RALP, 94 without the placement of suspension stitch (group 1) and 237 with the application of the suspension stitch (group 2). Surgical procedure: The only difference between the groups was the placement of the puboperiurethral stitch after the ligation of the dorsal venous complex (DVC). The periurethral retropubic stitch was placed using a 12-in monofilament polyglytone suture on a CTI needle. The stitch was passed from right to left between the urethra and DVC, and then through the periostium on the pubic bone. The stitch was passed again through the DVC, and then through the pubic bone in a figure eight, and then tied. Measurements: Continence rates were assessed with a self-administered validated questionnaire (Expanded Prostate Cancer Index Composite [EPIC] at 1, 3, 6, and 12 mo after the procedure. Continence was defined as the use of no absorbent pads or no leakage of urine. Results and limitations: In group 1, the continence rate at 1, 3, 6, and 12 mo postoperatively was 33%, 83%, 94.7%, and 95.7%, respectively; in group 2, the continence rate was 40%, 92.8%, 97.9%, and 97.9%, respectively. The suspension technique resulted in significantly greater continence rates at 3 mo after RALP (p = 0.013). The median/mean interval to recovery of continence was also statistically significantly shorter in the suspension group (median: 6 wk; mean: 7.338 wk: 95% confidence interval [CI]: 6.387-8.288) compared to the non-suspension group (median: 7 wk; mean: 9.585 wk: 95% CI: 7.558-11.612; log rank test, p = 0.02). Conclusions: The suspension stitch during RALP resulted in a statistically significantly shorter interval to recovery of continence and higher continence rates at 3 mo after the procedure. (C) 2009 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Morphological comparison of different protocols of skeletal muscle remobilization in rats after hindlimb suspension

The aim of this study was to evaluate and compare the efficacy of different remobilization protocols in different skeletal muscles considering the changes induced by hindlimb suspension of the tail. Thirty-six female Wistar rats were divided into six groups: control I, control II, suspended, suspended free, suspended trained on a declined treadmill and suspended trained on a flat treadmill. Fragments of soleus and tibialis anterior (TA) muscle were frozen and processed by different histochemical methods. The suspended soleus showed a significant increase in the proportional number of intermediate/hybrid fibers and a decrease in the number of type I fibers. Some of these changes proved to be reversible after remobilization. The three remobilization programs led to the recovery of both the proportional number of fibers and their size. The TA muscle presented a significant increase in the number and size of type I fibers and a cell size reduction of type IIB fibers, which were recovered after training on a declined treadmill and free movement. Especially regarding the soleus, the present findings indicate that, among the protocols, training on a declined treadmill was found to induce changes of a more regenerative nature, seemingly indicating a better tissue restructuring after the suspension procedure.

Effects of eccentric and concentric training on capillarization and myosin heavy chain contents in rat skeletal muscles after hindlimb suspension

We studied the effects of different protocols of post-disuse rehabilitation on angiogenesis and myosin heavy chain (MHC) content in rat hindlimb muscles after caudal suspension. Thirty female Wistar rats were divided into five groups: (1) Control I, (2) Control II, (3) Suspended, (4) Suspended trained on declined treadmill, and (5) Suspended trained on flat treadmill. Fragments of the soleus and tibialis anterior (TA) muscles were frozen and processed by electrophoresis and immunohistochemistry (CD31 antibody). Hindlimb suspension caused reduction of capillary/fiber (C/F) ratios and contents of MHC type I (MHCI) in the soleus in parallel to increased capillary density. Flat treadmill protocols increased the content of the MHCI isoform. The C/F ratio was increased by concentric training after hypokinesis, but was not modified by eccentric training, which caused a greater reduction of capillary density compared to the other protocols. In the TA muscle, hindlimb suspension caused a non-significant increase in capillary density and C/F ratio with limited changes in MHC. The present data demonstrate that the different training protocols adopted and the functional performance of the muscles analyzed caused specific changes in capillarization and in the content of the various MHC types. (C) 2010 Published by Elsevier GmbH.

Inferring migration flows from the migration propensities of infants: Mexico and Indonesia

The need for methods of indirectly estimating migration flows is particularly important in developing countries, where migration data are often incomplete and inaccurate. This paper focuses on the use of an indirect internal migration estimation method applied to Mexican and Indonesian census data. It shows that the mobility propensities of infants can be used to infer the corresponding propensities of all other age groups. However, the promise of this method is reduced in instances of inadequate data, and great care must be taken to identify outlying values in the data and to correct obviously erroneous patterns. Future work increasingly will be directed to this issue.

The measurement of actual acidity in acid sulfate soils and the determination of sulfidic acidity in suspension after peroxide oxidation

Improvements to the routine methods for the determination of actual acidity in suspension for acid sulfate soils (ASS) are introduced. The titratable sulfidic acidity (TSA) results using an improved peroxide-based method were compared with the theoretical acidity predicted by the chromium reducible sulfur method for 9 acid sulfate soils. The regression between these 2 measures of sulfidic acidity was highly significant, the slope of the regression line not significantly different from unity (P = 0.05) and the intercept not significantly different from zero. This contrasts with results of other workers using earlier peroxide oxidation methods, where TSA substantially underestimated the theoretical acidity predicted by reduced inorganic sulfur analysis. Comparison was made between the 2 principal measurements from the improved peroxide method (TSA and S-POS), with S-POS converted to theoretical sulfidic acidity to allow comparison. The relationship between these 2 measurements was highly significant. The effects of titration in suspension, as well as raising titration end points to pH 6.5, were investigated, principally with respect to the titratable actual acidity (TAA) result. TAA results obtained by KCl extraction were compared with those obtained using BaCl2, MgCl2, and water extraction. TAA in 1 M KCl suspensions titrated to pH 6.5 agreed well with titratable actual acidity measured using the 25-h extraction approach of the Lin et al. (2000a) BaCl2 method. Both BaCl2 and KCl solutions were ineffective at fully recovering acidity from synthetic jarosite without repeated extraction and titration. The application of correction factors for the estimation of total actual acidity in ASS is not supported by the results of this investigation. Acid sulfate soils that contain substantial quantities of jarosite or other acid-producing but relatively insoluble sulfate minerals continue to prove problematic to chemically analyse; however, an approach for estimating this component is discussed.