bluuebunny/crossref_metadata_2025 huggingface dataset:
Heat Transfer Enhancement Within a Turbine Blade Cooling Passage Using Ribs and Combinations of Ribs With Film Cooling Holes
Authors: Shen J. R. , Wang Z. , Ireland P. T. , Jones T. V. , Byerley A. R.
Published: August 2010

A transient heat transfer method using liquid crystals has been applied to a scale model of a turbine rotor blade passage. Detailed contours of local heat transfer coefficient are presented for the passage in which the heat transfer to one wall was enhanced first by ribs and then with ribs combined with holes. The hole geometry and experimental dimensionless flow rates were representative of those occurring at the entrance to engine film cooling holes. The results for the ribbed passage are compared to established correlations for developed flow. Qualitative surface shear stress distributions were determined with liquid crystals. The complex distributions of heat transfer coefficient are discussed in light of the interpreted flow field.
Local Heat Transfer in a Rotating Two-Pass Triangular Duct With Smooth Walls
Authors: Dutta S. , Han J.-C. , Zhang Y. , Lee C. P.
Published: August 2010

Earlier heat transfer studies with orthogonal rotation were conducted mostly on ducts of square cross section. This paper reports a different cross section, a triangular duct. Unlike a square cross section, the triangular shape provides more restriction to the formation of the secondary flows. Moreover, the studied orientation of the right triangular duct avoids formation of symmetric vortex structures in the crossflow plane. This paper presents turbulent heat transfer characteristics of a two-pass smooth-walled triangular duct. One pass is for radial outward flow and the other for radial inward flow. With rotation the radial outward and inward flow directions show different surface heat transfer characteristics. Like a square duct, differences between the trailing and the leading Nusselt number ratios for the triangular duct increase with rotation number. However, the rate of change of Nusselt number rations with rotation number varies for the two duct geometries. Standard k–ε model predictions for a radial outward flow situation show that the Nusselt number ratio variations with Reynolds number are not drastic for the same rotation number.
Heat Transfer in an Air-Cooled Rotor–Stator System
Authors: Chen J.-X. , Gan X. , Owen J. M.
Published: August 2010

This paper describes a combined experimental and computational study of the heat transfer from an electrically heated disk rotating close to an unheated stator. A radial outflow of cooling air was used to remove heat from the disk, and local Nusselt numbers were measured, using fluxmeters at seven radial locations, for nondimensional flow rates up to Cw = 9680 and rotational Reynolds numbers up to Reφ = 1.2 × 106 Computations were carried out using an elliptic solver with a low-Reynolds-number k–ε turbulence model, and the agreement between the measured and computed velocities and Nusselt numbers was mainly good.
Calculation of Three-Dimensional Viscous Flow in Hydrodynamic Torque Converters
Authors: Schulz H. , Greim R. , Volgmann W.
Published: August 2010

A numerical method for calculating three-dimensional, steady or unsteady, incompressible, viscous flow is described. The conservation equations for mass and momentum and the equations of the k–ε turbulence model are solved with a finite volume method on nonorthogonal boundary-fitted grids. The method employs cell-centered variable arrangement and Cartesian velocity components. The SIMPLE algorithm is used to calculate the pressure and to enforce mass conservation. The computer code is vectorizable as far as possible to achieve an optimal performance on modern vector computers. Results of steady flow calculations in the guide vane, the pump rotor, and the turbine rotor and of the unsteady interaction simulation of the pump and the turbine of a one-stage one-phase non-automotive hydrodynamic torque converter are presented.
LDA Investigation of the Flow Development Through Rotating U-Ducts
Authors: Cheah S. C. , Iacovides H. , Jackson D. C. , Ji H. , Launder B. E.
Published: August 2010

This paper reports results from the use of laser-Doppler anemometry (LDA) to measure the mean and fluctuating flow field in a U-bend of strong curvature, Rc/D = 0.65, that is either stationary or rotating in orthogonal mode (the axis of rotation being parallel to the axis of curvature). The data acquisition system enables a stationary optical fiber probe to collect flow data from a rotating U-bend sweeping past it. Three cases have been examined, all concerning a flow Reynolds number of 100,000; a stationary case, a case of positive rotation (the pressure side of the duct coincides with the outer side of the U-bend) at a rotational number (ΩD/Um) of 0.2, and a case of negative rotation at a rotational number of −0.2. Measurements have been obtained along the symmetry plane of the duct and also along a plane near the top wall. The most important influence on the development of the mean and turbulence flow fields is exerted by the streamwise pressure gradients that occur over the entry and exit regions of the U-bend. In the stationary case a three-dimensional separation bubble is formed along the inner wall at the 90 deg location and it extends to about two diameters downstream of the bend, causing the generation of high-turbulence levels. Along the outer side, opposite the separation bubble, turbulence levels are suppressed due to streamwise flow acceleration. For the rotation numbers examined, the Coriolis force also has a significant effect on the flow development. Positive rotation doubles the length of the separation bubble and generally suppresses turbulence levels. Negative rotation causes an extra separation bubble at the bend entry, raises turbulence levels within and downstream of the bend, increases velocity fluctuations in the cross-duct direction within the bend, and generates strong secondary motion after the bend exit. It is hoped that the detailed information produced in this study will assist in the development of turbulence models suitable for the numerical computation of flow and heat transfer inside blade-cooling passages.
Thermoacoustic Modeling of a Gas Turbine Using Transfer Functions Measured Under Full Engine Pressure
Authors: Schuermans Bruno , Guethe Felix , Pennell Douglas , Guyot Daniel , Paschereit Christian Oliver
Published: August 2010

Thermoacoustic transfer functions of a full-scale gas turbine burner operating under full engine pressure have been measured. The excitation of the high-pressure test facility was done using a siren that modulated a part of the combustion airflow. Pulsation probes have been used to record the acoustic response of the system to this excitation. In addition, the flame’s luminescence response was measured by multiple photomultiplier probes and a light spectrometer. Three techniques to obtain the thermoacoustic transfer function are proposed and employed: two acoustic-optical techniques and a purely acoustic technique. The first acoustical-optical technique uses one single optical signal capturing the chemiluminescence intensity of the flame as a measure for the heat release in the flame. This technique only works if heat release fluctuations in the flame have only one generic source, e.g., equivalence ratio or mass flow fluctuations. The second acoustic-optical technique makes use of the different response of the flame’s luminescence at different optical wavelengths bands to acoustic excitation. It also works, if the heat release fluctuations have two contributions, e.g., equivalence ratio and mass flow fluctuation. For the purely acoustic technique, a new method was developed in order to obtain the flame transfer function, burner transfer function, and flame source term from only three pressure transducer signals. The purely acoustic method could be validated by the results obtained from the acoustic-optical techniques. The acoustic and acoustic-optical methods have been compared and a discussion on the benefits and limitations of each is given. The measured transfer functions have been implemented into a nonlinear, three-dimensional, time domain network model of a gas turbine with an annular combustion chamber. The predicted pulsation behavior shows a good agreement with pulsation measurements on a field gas turbine.
Numerical Prediction of Void Distribution in Two-Phase Turbulent Flow in a Subchannel
Authors: Ikeno Tsutomu , Sasakawa Tatsuya , Kataoka Isao
Published: August 2010

Numerical simulation code for predicting void distribution in two-phase turbulent flow in a subchannel was developed. The purpose is to obtain a profile of void distribution in the subchannel. The result will be used for predicting a heat flux at departure from nucleate boiling in a rod-bundle for the pressurized water reactor (PWR). The fundamental equations were represented by a generalized transport equation and the transport equation was transformed onto the generalized coordinate system fitted to the rod surface and the symmetric lines in the subchannel. Using the finite-volume method the transport equation was discretized for the SIMPLE algorithm. The flow field and void fraction at the steady-state were calculated for different average void fractions. The computational result for atmospheric pressure condition was successfully compared with experimental data. Sensitivity analysis for the PWR condition was performed, and the result showed that the secondary flow slightly contributed to homogenizing the void distribution.
Effects of B20 on Emissions and the Performance of a Diesel Particulate Filter in a Light-Duty Diesel Engine
Authors: Peterson Amy M. , Lee Po-I , Lai Ming-Chia , Wu Ming-Cheng , DiMaggio Craig L. , Ng Simon , Tang Hiyang
Published: August 2010

This paper compares 20% biodiesel (B20-choice white grease) fuel with baseline ultra low sulfur diesel (ULSD) fuel on the emissions and performance of a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) coupled to a light duty four-cylinder 2.8-l common-rail DI diesel engine. The present paper focuses on the comparison of the fuel effects on loading and active regeneration of the DPF between B20 and ULSD. B20, in general, produces less soot and has lower regeneration temperature, compared with soot loaded with ULSD. NO2 concentrations before the DPF were found to be 6% higher with B20, indicating more availability of NO2 to oxidize the soot. Exhaust speciation of the NO2 availability indicates that the slight increase in NOx from B20 is not the dominant cause for the lower temperature regeneration and faster regeneration rate, but the reactivity of the soot that is in the DPF. Formaldehyde concentrations are found to be higher with B20 during regeneration, due to increased oxygen concentrations in the exhaust stream. Finally, the oil dilution effect due to post injection to actively regenerate the DPF is also investigated using a prototype oil sensor and Fourier transform infrared (FTIR) instrumentation. Utilizing an active regeneration strategy accentuates the possibility of fuel oil dilution of the engine oil. The onboard viscosity oil sensor used was in good agreement with the viscosity bench test and FTIR analysis, and provided oil viscosity measurement over the course of the project. The operation with B20 shows significant fuel dilution and needs to be monitored to prevent engine deterioration.
ASTEC, COCOSYS, and LIRIC Interpretation of the Iodine Behavior in the Large-Scale THAI Test Iod-9
Authors: Weber G. , Bosland L. , Funke F. , Glowa G. , Kanzleiter T.
Published: August 2010

The large-scale iodine test Iod-9 of the German Thermal hydraulics, Hydrogen, Aerosols, Iodine (THAI) program was jointly interpreted by means of post-test analyses within the THAI Circle of the Severe Accident Research NETwork (SARNET)/Work Package 16. In this test, molecular iodine (I2) was injected into the vessel dome of the 60 m3 THAI vessel to observe the evolution of its distribution between water, gas, and surfaces. The main processes addressed in Iod-9 are (a) the mass transfer of I2 between the gas and the two sumps, (b) the iodine transport in the main sump when it is stratified and then mixed, and (c) the I2 adsorption onto, and desorption from, the vessel walls in the presence and absence of wall condensation. The codes applied by the THAI Circle partners were the Accident Source Term Evaluation Code (ASTEC)-IODE (IRSN, Saint Paul Lez Durance, France), Containment Code System (COCOSYS)-Advanced Iodine Model (AIM) (GRS, Garching, Germany), and Library of Iodine Reactions in Containment (LIRIC; AECL, Chalk River, ON, Canada). ASTEC-IODE and the Advanced Iodine Model (AIM) are semi-empirical iodine models integrated in the lumped-parameter codes ASTEC and COCOSYS, respectively. With both codes multicompartment iodine calculations can be performed. LIRIC is a mechanistic iodine model for single stand-alone calculations. The simulation results are compared with each other and with the experimental measurements. Special issues that were encountered during this work were studied in more details: I2 diffusion in the sump water, I2 reaction with the steel of the vessel wall in gaseous and aqueous phases, and I2 mass transfer from the gas to the sump. Iodine transport and behavior in THAI test Iod-9 are fairly well simulated by ASTEC-IODE, COCOSYS-AIM, and LIRIC in post-test calculations. The measured iodine behavior is well understood and all measured data are found to be consistent. The very slow iodine transport within the stratified main sump was simulated with COCOSYS only, in a qualitative way. Consequently, this work highlighted the need to improve modeling of (a) the wet iodine adsorption and the washdown from the walls, (b) the I2 mass transfer between gas and sump, and (c) the I2/steel reaction in the gaseous and aqueous phases. In any case, the analysis of the large-scale iodine test Iod-9 has been an important validation step for the codes applied.
Simultaneous Type and Dimensional Synthesis of Planar 1DOF Mechanisms Using Evolutionary Search and Convertible Agents (DETC2009-86722)
Authors: Oliva John C. , Goodman Erik D.
Published: August 2010

This paper introduces a novel approach to automated mechanism synthesis called “convertible agents.” The evolutionary computing technique has been developed specifically for the unique design challenges encountered when synthesizing a mechanism for both type and dimensionality. Several case studies are presented, which demonstrate the approach’s effectiveness over earlier solution strategies. In these studies, six different planar single-degree-of-freedom mechanism types are considered: a four-bar mechanism, Stephenson’s six-bar-mechanisms (types I, II, and III), and Watt’s six-bar-mechanisms (types I and II). The synthesis technique selects the best suited mechanism type from this set and optimizes its dimensions to meet the design objective at hand. The method is readily scalable to account for any number of different mechanism types and complexities.
Interactive Dimensional Synthesis and Motion Design of Planar 6R Single-Loop Closed Chains via Constraint Manifold Modification
Authors: Wu Jun , Purwar Anurag , Ge Q. J.
Published: August 2010

In this paper, we present an interactive, visual design approach for the dimensional synthesis of planar 6R single-loop closed chains for a given rational motion using constraint manifold modification. This approach is implemented in an interactive software tool that provides mechanism designers with an intuitive way to determine the parameters of planar mechanisms, and in the process equips them with an understanding of the design process. The theoretical foundation of this work is based on representing planar displacements with planar quaternions, which can be seen as points in a special higher dimensional projective space (called the image space), and on formulating the kinematic constraints of closed chains as algebraic surfaces in the image space. Kinematic constraints under consideration limit the positions and orientation of the coupler in its workspace. In this way, a given motion of a mechanism in the Cartesian space maps to a curve in the image space that is limited to stay within the bounds of the algebraic surfaces. Thus, the problem of dimensional synthesis is reduced to determine the parameters of equations that describe algebraic surfaces. We show that the interactive approach presented here is general in nature, and can be easily used for the dimensional synthesis of any mechanism for which kinematic constraints can be expressed algebraically. The process of designing is fast, intuitive, and especially useful when a numerical optimization based approach would be computationally demanding and mathematically difficult to formulate. This simple approach also provides a basis for students and early designers to learn and understand the process of mechanism design by simple geometric manipulations.
Second Law Analysis of Heat Exchangers
Authors: Fakheri Ahmad
Published: August 2010

This paper further explores the topic of an ideal heat exchanger, which is still an open question. It is shown that the minimization of entropy production or exergy destruction should not be an objective in heat exchanger design. It is further proven that heat exchanger effectiveness does not correlate with irreversibility. A new performance measure, entropy flux, is introduced and a general expression for its evaluation is presented. It is shown that entropy flux captures many desirable attributes of heat exchangers. For a given effectiveness, a single stream heat exchanger has the absolute maximum entropy flux, and for capacity ratios greater than zero, counterflow has the highest entropy flux, parallel flow the lowest, and the shell and tube heat exchangers are somewhere in between.
A Four-Step Fixed-Grid Method for 1D Stefan Problems
Authors: Tadi M.
Published: August 2010

This note is concerned with a fixed-grid finite difference method for the solution of one-dimensional free boundary problems. The method solves for the field variables and the location of the boundary in separate steps. As a result of this decoupling, the nonlinear part of the algorithm involves only a scalar unknown, which is the location of the moving boundary. A number of examples are used to study the applicability of the method. The method is particularly useful for moving boundary problems with various conditions at the front.
Multivalent Integrin-Specific Ligands Enhance Tissue Healing and Biomaterial Integration
Authors: Petrie Timothy A. , Raynor Jenny E. , Dumbauld David W. , Lee Ted T. , Jagtap Subodh , Templeman Kellie L. , Collard David M. , García Andrés J.
Published: August 2010

Titanium implants coated with nanoclustered ligands for integrin adhesion receptors are tightly integrated into bone for orthopedic applications.
360 Degrees of Human Subjects Protections in Community-Engaged Research
Authors: Ross Lainie Friedman
Published: August 2010

When communities are both participants and partners in research, effective human subjects protections must address both individual and group risks.
Hot Peppers to Cool Blood Pressure
Authors: Buettner Christoph
Published: August 2010

Feeding hypertensive rodents the pungent compound capsaicin reduces their blood pressure via activation of a cation channel.
The Heart of “Stemness”
Authors: Morozov Alexei
Published: August 2010

A regulator of asymmetric cell division promotes the transition to blast crisis in chronic myelogenous leukemia.
LEM-PCR: a method for determining relative transcript isoform proportions using real-time PCR without a standard curve
Authors: Virtue S. , Dale M. , Sethi J. K. , Vidal-Puig A.
Published: August 2010

Many genes express multiple transcript isoforms generated by alternative splicing of mRNA. Using real-time PCR, it is straightforward to determine the relative expression level of each isoform independently. However, it is less trivial to determine the relative proportions of different isoforms in a cDNA sample. The relative proportions of different isoforms can be important, as a small change in a highly abundant transcript may be more relevant than a large change in a minimally expressed transcript. Currently, determining the relative proportions of isoforms requires the construction of a standard curve using recombinant plasmid DNA or genomic DNA. As recombinant or genomic DNA standards often amplify with different efficiencies to cDNA samples, they may give under- or overestimations of isoform abundances. The method described in this article uses a titration curve generated from the same cDNA samples measured in the experiment. By using samples with different levels of separate isoforms, it is possible to derive linear equations which, when solved, allow the determination of the proportion of each isoform within the samples under study.
Peripheral expression of inflammatory markers in overweight female adolescents and eutrophic female adolescents with a high percentage of body fat
Authors: Carvalho Gisele Queiroz , Pereira Patrícia Feliciano , Serrano Hiara Miguel Stancioli , do Carmo Castro Franceschini Sylvia , Oliveira de Paula Sérgio , Priore Silvia Eloiza , do Carmo Gouveia Peluzio Maria
Published: August 2010

The objective of this study was to evaluate the peripheral expression of inflammatory markers in adolescents with different nutritional status and its correlation with parameters of the metabolic syndrome. Seventy-two female postpubescent adolescents were divided into 3 groups: eutrophic (Co), eutrophic with a high body fat percentage (HBF), and overweight (OW). Data related to the parameters of the metabolic syndrome and the peripheral expression of tumour necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10 were evaluated. Higher values of glycemia and insulin resistance were found in the HBF group than in the Co group. No differences related to the peripheral expression of the cytokines were found among the groups. In the HBF group, a positive correlation was observed between TNF-α and IL-6, IL-10 and the proinflammatory cytokines, and IL-6 and glycemia. In the OW group, a positive correlation was found between IL-6 and triglycerides. Adolescents with normal weight but body fat excess present a metabolic profile and body composition similar to those of overweight adolescents. This suggests that these adolescents have a risk of developing cardiovascular diseases similar to that of overweight adolescents. The positive correlation between IL-10 and TNF-α and IL-6 suggests an attempt to inhibit the production of these cytokines by IL-10.
Palm cooling does not reduce heat strain during exercise in a hot, dry environment
Authors: Amorim Fabiano T. , Yamada Paulette M. , Robergs Robert A. , Schneider Suzanne M.
Published: August 2010

To compare the effectiveness of the rapid thermal exchange device (RTX) in slowing the development of hyperthermia and associated symptoms among hand immersed in water bath (WB), water-perfused vest (WPV), and no cooling condition (NC). Ten subjects performed 4 heat stress trials. The protocol consisted of 2 bouts of treadmill walking, separated by a cooling–rehydration period. The times to reach the predetermined rectal temperature in the first (38.5 °C) and second bouts (39 °C) were not different among RTX, NC, and WB, but was longer for the WPV in both bouts (p < 0.05). Heat storage was significantly lower for WPV only in the first bout vs. the other conditions (p < 0.05). Heart rate (HR) was not different at 10, 20, and 30 min during the first bout among RTX, NC, and WB, but was lower for WPV (p < 0.05). HR was not different among conditions during the second bout. The RTX was not effective in slowing the development of hyperthermia.
Influence of high- and low-carbohydrate diet following glycogen-depleting exercise on heart rate variability and plasma catecholamines
Authors: Lima-Silva Adriano Eduardo , Bertuzzi Rômulo , Dalquano Elen , Nogueira Marie , Casarini Dulce , Kiss Maria Augusta , Ugrinowitsch Carlos , Pires Flávio de Oliveira
Published: August 2010

The purpose of this study was to investigate the effects of a short-term low- or high-carbohydrate (CHO) diet consumed after exercise on sympathetic nervous system activity. Twelve healthy males underwent a progressive incremental test; a control measurement of plasma catecholamines and heart rate variability (HRV); an exercise protocol to reduce endogenous CHO stores; a low- or high-CHO diet (counterbalanced order) consumed for 2 days, beginning immediately after the exercise protocol; and a second resting plasma catecholamine and HRV measurement. The exercise and diet protocols and the second round of measurements were performed again after a 1-week washout period. The mean (±SD) values of the standard deviation of R–R intervals were similar between conditions (control, 899.0 ± 146.1 ms; low-CHO diet, 876.8 ± 115.8 ms; and high-CHO diet, 878.7 ± 127.7 ms). The absolute high- and low-frequency (HF and LF, respectively) densities of the HRV power spectrum were also not different between conditions. However, normalized HF and LF (i.e., relative to the total power spectrum) were lower and higher, respectively, in the low-CHO diet than in the control diet (mean ± SD, 17 ± 9 normalized units (NU) and 83 ± 9 NU vs. 27 ± 11 NU and 73 ± 17 NU, respectively; p < 0.05). The LF/HF ratio was higher with the low-CHO diet than with the control diet (mean ± SD, 7.2 ± 6.2 and 4.2 ± 3.2, respectively; p < 0.05). The mean values of plasma catecholamines were not different between diets. These results suggest that the autonomic control of the heart rate was modified after a short-term low-CHO diet, but plasma catecholamine levels were not altered.
Effect of intermittent hypoxia on muscle and cerebral oxygenation during a 20-km time trial in elite athletes: a preliminary report
Authors: Hamlin Michael J. , Marshall Helen C. , Hellemans John , Ainslie Philip N.
Published: August 2010

The effects of intermittent hypoxic exposure (IHE) on cerebral and muscle oxygenation, arterial oxygen saturation (SaO2), and respiratory gas exchange during a 20-km cycle time trial (20TT) were examined (n = 9) in a placebo-controlled randomized design. IHE (7:3 min hypoxia to normoxia) involved 90-min sessions for 10 days, with SaO2clamped at ∼80%. Prior to, and 2 days after the intervention, a 20TT was performed. During the final minute of the 20TT, in the IHE group only, muscle oxyhemoglobin (oxy-Hb) was elevated (mean ± 95% confidence interval 1.3 ± 1.2 ΔµM, p = 0.04), whereas cerebral oxy-Hb was reduced (–1.9% ± 1.0%, p < 0.01) post intervention compared with baseline. The 20TT performance was unchanged between groups (p = 0.7). In the IHE group, SaO2was higher (1.0 ± 0.7Δ%, p = 0.006) and end-tidal PCO2was lower (–1.2 ± 0.1 mm Hg, p = 0.01) during the final stage of the 20TT post intervention compared with baseline. In summary, reductions in muscle oxy-Hb and systemic SaO2occurring at exercise intensities close to maximal at the end of a 20TT were offset by IHE, although this was not translated into improved performance.
Individual exercise sessions alter circulating hormones and cytokines in HIV-infected men
Authors: Dudgeon Wesley David , Phillips Kenneth Doyle , Durstine John Larry , Burgess Stephanie E. , Lyerly George William , Davis John Mark , Hand Gregory Allen
Published: August 2010

Exercise has the potential to impact disease by altering circulating anabolic and catabolic factors. It was the goal of this study to determine how different regimens of low-intensity and moderate-intensity exercise affected circulating levels of these anabolic and catabolic factors in HIV-infected men. Exercise-naive, HIV-infected men, medically cleared for study participation, were randomized into one of the following groups: a moderate-intensity group (MOD, who completed 30 min of moderate-intensity aerobic training followed by 30 min of moderate-intensity resistance training; a low-intensity group (LOW), who completed 60 min of treadmill walking; or a control group (CON), who attended the clinic but participated in no activity. Blood and saliva samples were collected at selected time points before, during, and after each of the 3 required sessions. Compared with baseline, the MOD group (n = 14) had a 135% increase in growth hormone (GH) (p < 0.05) and a 34% decrease in cortisol (CORT) (p < 0.05) at the post time point, a 31% increase in interleukin-6 (IL-6) (p < 0.05) at 30-min post exercise, and a 23% increase in IL-6 (p < 0.05) and a 13% decrease in soluble tumor necrosis factor receptor 2 (sTNFrII) (p < 0.05) at 60-min post exercise. The LOW (n = 11) group had a 3.5% decrease in sTNFrII (<0.05) at 30-min post exercise compared with baseline and a 49% decrease (p < 0.05) in GH at 60-min post exercise. The CON group (n = 13) had a decrease in GH at 30-min (62%, p < 0.05) and 60-min (61%, p < 0.05) post exercise compared with baseline. The increase in GH from baseline to post was greater in the MOD group (p < 0.05) and the decrease in CORT from pre to post was greater in the MOD group (p < 0.05) than in the other groups. These data suggest that individual sessions of both low-intensity and moderate-intensity exercise can alter circulating anabolic and catabolic factors in HIV-infected men. The changes in the MOD group present potential mechanisms for the increases in lean tissue mass seen with resistance exercise training.
Quiet and durable pavements: Findings from an Ontario study
Authors: Ahammed M. Alauddin , Tighe Susan L. , Klement Tom
Published: August 2010

Traffic noise is a growing problem throughout the world. Noise barriers, traditionally used for reducing noise exposure, are expensive and inefficient in some cases. Pavement surface characteristics play a key role in noise generation and propagation. Information about noise-reducing characteristics of various Portland cement concrete (PCC) and asphalt concrete (AC) pavements can therefore help public agencies in selecting an appropriate surface that maximizes the structural durability, reduces the noise, and ensures adequate skid resistance for safety. In this study, tire–pavement close proximity (CPX), in-vehicle, and controlled pass-by (CPB) noise were measured at 80–100 km/h for 32 PCC and AC pavements in southern Ontario. The results have indicated that certain textures are needed to allow for air escape from the tire–road interface, which limits the generation and (or) propagation of tire–pavement noise. Both fine-graded Superpave and stone mastic asphalt (SMA) were shown to be promising for noise reduction and have good durability characteristics. However, careful placement and finishing are essential to produce a uniform lower order macrotexture and to attain the noise-reduction benefit.
Intramolecular hydroamination of unactivated alkenes with secondary alkylamines catalyzed by iridium phosphino–phenolate complexes
Authors: Hesp Kevin D. , McDonald Robert , Stradiotto Mark
Published: August 2010

The phosphino–phenolate complex (κ2-{2-i-Pr2PC6H4}O)Ir(COD) (COD = η4-1,5-cyclooctadiene; 1) is shown to be an effective precatalyst for the intramolecular hydroamination of unactivated alkenes with pendant secondary alkylamines, providing either pyrrolidine or piperidine heterocycles in high isolated yields. While monitoring the progress of a selected test reaction of this type, a significant induction period (~3 h) was observed; variable-temperature 1H and 31P NMR studies (25–100 °C) under catalytically relevant conditions revealed no new metal-containing species. In an effort to develop an enantiopure variant of 1, a synthetic route to the chiral (κ2-P,O)Ir(COD) complex (7), which features a 1-aryl-2,5-dialkylphospholane structure derived from (2S,5S)-2,5-hexanediol cyclic sulfate, was developed. The structure of 7 was confirmed by use of single-crystal X-ray diffraction techniques. While 7 failed to provide enantioselectivity in the intramolecular hydroamination of unactivated alkenes with pendant secondary alkylamines, the activity of 7 was found to be comparable to that of 1.
An ab initio study of model triazene-based anticancer agents
Authors: Doucet Katherine G. , Glister Julie F. , Pye Cory C.
Published: August 2010

A computational study of a series of model triazene-based anticancer agents based on methyl- and amidyl-substituted 5-(1-triazenyl)imidazoles has been carried out, including the drugs Dacarbazine, Temozolomide, and Mitozolomide. A number of different conformers are analyzed. The transition states for the gas-phase and water-mediated triazene tautomerization reaction are found and the barriers are determined.
Density functional theory study on the electron spectra of naphthalene and azulene vapours
Authors: Chong Delano P.
Published: August 2010

The ionization and excitation spectra of valence and core electrons of naphthalene and azulene in the gas phase are studied with density functional theory. The results are compared with available experimental data and previous calculations. New estimates are proposed for the ionization energies of both valence and core electrons and the calculated excitation energies are consistent with experiment.
Theoretical analysis of the (HNO)2, (HNO···HNS), and (HNS)2 dimers — A case of red and blue shifts of N–H stretching frequency
Authors: Trung Nguyen Tien , Hue Tran Thanh , Nguyen Minh Tho
Published: August 2010

The hydrogen-bonded interactions in the simple (HNZ)2 dimers, with Z = O and S, were investigated using quantum chemical calculations with the second-order Møller–Plesset perturbation (MP2), coupled-cluster with single, double (CCSD), and triple excitations (CCSD(T)) methods in conjunction with the 6-311++G(2d,2p), aug-cc-pVDZ, and aug-cc-pVTZ basis sets. Six-membered cyclic structures were found to be stable complexes for the dimers (HNO)2, (HNS)2, and (HNO–HNS). The pair (HNS)2 has the largest complexation energy (–11 kJ/mol), and (HNO)2 the smallest one (–9 kJ/mol). A bond length contraction and a frequency blue shift of the N–H bond simultaneously occur upon hydrogen bond formation of the N–H···S type, which has rarely been observed before. The stronger the intramolecular hyperconjugation and the lower the polarization of the X–H bond involved as proton donor in the hydrogen bond, the more predominant is the formation of a blue-shifting hydrogen bond.
Factors influencing the persistence ofEscherichia coliO157:H7 lineages in feces from cattle fed grain versus grass hay diets
Authors: Lowe Ross M.S. , Munns Krysty , Selinger L. Brent , Kremenik Linda , Baines Danica , McAllister Tim A. , Sharma Ranjana
Published: August 2010

Escherichia coli O157:H7 is a pathogenic, gram-negative bacterium that causes diarrhea, hemorrhagic colitis, and can lead to fatal hemolytic uremic syndrome in humans. We examined the persistence of E. coli O157:H7 lineages I and II in feces held at 4, 12, and 25 °C, from animals fed either grain or hay diets. Three strains of each lineage I and II were inoculated into grain-fed or hay-fed feces, and their persistence was monitored over 28 days. No significant differences in E. coli O157:H7 survival between the 2 lineages in both fecal types was found at the examined temperatures. Volatile fatty acids were higher in grain-fed than in hay-fed feces, resulting in consistently lower pH in the grain-fed feces at 4, 12 and 25 °C. Regardless of lineage type, E. coli O157:H7 CFUs were significantly higher in grain-fed than in hay-fed feces at 4 and 25 °C. Escherichia coli O157:H7 survival was highest in grain-fed feces at 25 °C up to 14 days. Our results indicate that the 2 lineages of E. coli O157:H7 do not differ in their persistence; however, it appears that temperature and feces type both affect the survival of the pathogen.
Endothelin axis induces metalloproteinase activation and invasiveness in human lymphatic endothelial cellsThis article is one of a selection of papers published in the two-part special issue entitled 20 Years of Endothelin Research.
Authors: Spinella Francesca , Caprara Valentina , Garrafa Emirena , Di Castro Valeriana , Rosanò Laura , Natali Pier Giorgio , Bagnato Anna
Published: August 2010

The molecular mechanisms involved in lymphangiogenesis were unknown until recently. We previously demonstrated that the endothelin-1 (ET-1) axis stimulates lymphatic endothelial cells (LEC) and lymphatic vessels to grow and invade. Here we further investigated the effect of ET-1 on lymphatic vessels and evaluated whether ET-1 actions result in the functional activation of lymphangiogenesis. Using highly purified human LEC, characterized for the expression of ET-1 axis members by quantitative real-time PCR, we found that the endothelin B receptor (ETB), upon activation by ET-1, induced matrix-metalloproteinase activation, demonstrating that ET-1 influenced the activity of the proteolytic enzymes required for LEC invasion. Functional assays performed by using intradermal lymphangiography demonstrated that ET-1 promoted the formation of lymphatic vessels and that these vessels were capable of lymphatic flow. ETB blockade with the specific antagonist BQ788 inhibited matrix-metalloproteinase activation and dye transport within the lymphatic vessels, demonstrating that ETB is involved in the regulation of the growth of and in the formation of functional vessels upon activation by ET-1. Our results suggest that ET-1 is a lymphangiogenic mediator and that targeting pharmacologically ETB may be therapeutically exploited in a variety of diseases, including cancer.
ECE-1 influences prostate cancer cell invasion via ET-1-mediated FAK phosphorylation and ET-1-independent mechanismsThis article is one of a selection of papers published in the two-part special issue entitled 20 Years of Endothelin Research.
Authors: Whyteside A. R. , Hinsley E. E. , Lambert L. A. , McDermott P. J. , Turner A. J.
Published: August 2010

Plasma concentrations of the mitogenic peptide endothelin-1 (ET-1) are significantly elevated in men with metastatic prostate cancer (PC). ET-1 also contributes to the transition of hormonally regulated androgen-dependent PC to androgen-independent disease. ET-1 is generated from big-ET-1 by endothelin-converting enzyme (ECE-1). ECE-1 is present in PC cell lines and primary tissue and is elevated in primary malignant stromal cells compared with benign. siRNA or shRNA-mediated knockdown of endogenous ECE-1 in either the epithelial or stromal compartment significantly reduced PC cell (PC-3) invasion and migration. The re-addition of ET-1 only partially recovered the effect, suggesting ET-1-dependent and -independent functions for ECE-1 in pPC. The ET-1-independent effect of ECE-1 on PC invasion may be due to modulation of downstream signalling events. Addition of an ECE-1 specific inhibitor to PC-3 cells reduced phosphorylation of focal adhesion kinase (FAK), a signalling molecule known to play a role in PC. siRNA-mediated knockdown of ECE-1 resulted in a significant reduction in FAK phosphorylation. Accordingly, transient ECE-1 overexpression in PNT1-a cells increased FAK phosphorylation. In conclusion, ECE-1 influences PC cell invasion via both ET-1-mediated FAK phosphorylation and ET-1 independent mechanisms.
Endothelin-1 induces pulmonary but not aortic smooth muscle cell migration by activating ERK1/2 MAP kinaseThis article is one of a selection of papers published in the two-part special issue entitled 20 Years of Endothelin Research.
Authors: Meoli David F. , White R. James
Published: August 2010

Endothelin 1 (ET-1) is an endogenous peptide that promotes vasoconstriction, endothelial and smooth muscle cell (SMC) proliferation, and fibrosis. ET-1 receptor antagonists are an important treatment strategy for pulmonary arterial hypertension, but less effective in systemic vascular disease. This observation suggests a special role for ET-1 in the pulmonary circulation. We hypothesized that ET-1 contributes to the pathogenesis of pulmonary arterial hypertension, in part, by promoting pulmonary vascular SMC migration. ET-1 treatment promoted migration in 3 distinct types of cultured pulmonary SMC. Pulmonary SMC migration was blocked by an ETA receptor selective agonist and a combined ETA–ETB antagonist, but not by a selective ETB antagonist. In contrast to the effect on pulmonary SMCs, ET-1 had no effect on migration of aortic SMCs. Flow cytometry showed that the ETA receptor was expressed at comparable levels on pulmonary and aortic SMCs, excluding receptor density as an explanation for the divergent effect. ET-1-induced pulmonary SMC migration was blocked by the structurally distinct MEK inhibitors PD98059 and U0126, consistent with a role for ERK1/2 MAP kinase. By Western blot in cultured cells and immunohistochemistry in ex vivo vessels, ET-1 stimulated phosphorylation of ERK1/2 as efficaciously as platelet-derived growth factor in pulmonary, but not aortic, SMCs. In conclusion, ET-1 induces SMC migration, with the ETA receptor tightly coupled to ERK1/2 phosphorylation only in the pulmonary circulation. This finding may help explain the striking difference in the efficacy of endothelin receptor blockers for pulmonary hypertension as compared to that for systemic cardiovascular disease.
LINGCOD MUSCLE NUCLEASE
Authors: Tomlinson Neil
Published: August 2010

A nuclease from muscle of lingcod (Ophiodon elongatus) has been purified by chromatography on diethylaminoethyl cellulose in the free-base form by stepwise elution with increasing concentrations of tris(hydroxymethyl)aminomethane. HCl, pH 7.0. The nuclease has been shown to hydrolyze ribonucleic acid, adenosine 3′-benzyl phosphate, thymidine 3′-p-nitrophenyl phosphate, and thymidine 5′-p-nitrophenyl phosphate. The latter compound was hydrolyzed at a very low rate. It did not hydrolyze adenosine 2′- or 5′- benzyl phosphate or certain nucleoside cyclic phosphates. The enzyme was inhibited by monoiodoacetate but not by heparin.
SYNTHESIS OF SATURATED AND UNSATURATEDL-α-LECITHINS ACYLATION OF THE CADMIUM CHLORIDE COMPOUND OFL-α-GLYCERYLPHOSPHORYLCHOLINE
Authors: Baer Erich , Buchnea Dmytro
Published: August 2010

A facile procedure for the preparation of saturated and unsaturated L-α-lecithins from L-α-glycerylphosphorylcholine (GPC) is reported. The lecithins are obtained by acylating L-α-GPC, in the form of its cadmium chloride addition compound, with fatty acid chloride and pyridine at low temperature (0°–25°). The acylation proceeds rapidly and yields optically pureL-α-lecithins. The preparation of the distearoyl-, dimyristoyl-, and dioleoyl L-α-lecithins by this procedure is described.The deacylation of lecithins with mercuric chloride or sodium hydroxide was investigated. Both procedures give a partially racemized L-α-GPC. This was established by the finding that the optical activity of the lecithins resulting from reacylating the L-α-GPC preparations in the form of their cadmium chloride compounds was considerably lower than that of the corresponding authentic lecithins.
ROLE OF PHOSPHOLIPIDS IN MITOCHONDRIAL RESPIRATION
Authors: Petrushka E. , Quastel J. H. , Scholefield P. G.
Published: August 2010

The addition of heated snake venom solutions to suspensions of rat liver, kidney, or brain mitochondria results in an initial stimulation of the rate of respiration, which is approximately the same for a variety of substrates, followed by a rapid decline.The presence of phospholipase A in heated snake venom is demonstrated by the formation of lysolecithin from mitochondrial lecithin. Various phospholipids, when added to mitochondria, have a protective influence against the inhibitory effects of phospholipase of heated venoms on respiration. Clostridium welchii toxin, which contains phospholipase C, has an effect on mitochondrial respiration which is similar to that of venom phospholipase A but the addition of phospholipid has no protective effect.Glutathione exercises a protective action against the inhibitory effects of phospholipase A on rat liver or kidney mitochondrial respiration, the action consisting of a prolongation of the initial stimulated phase of respiration. The effect does not seem to obtain with rat brain mitochondria.Exposure of rat brain cortex slices, but not those of rat kidney or liver, to heated venom results in changes of respiratory rates similar to those obtained with brain mitochondria.
A CLASSICAL MECHANICAL MODEL OF BROWNIAN MOTION WITH PLURAL PARTICLES
Authors: KUSUOKA SHIGEO , LIANG SONG
Published: August 2010

We give a connection between diffusion processes and classical mechanical systems in this paper. Precisely, we consider a system of plural massive particles interacting with an ideal gas, evolved according to classical mechanical principles, via interaction potentials. We prove the almost sure existence and uniqueness of the solution of the considered dynamics, prove the convergence of the solution under a certain scaling limit, and give the precise expression of the limiting process, a diffusion process.
IMPROVING THE ENTANGLEMENT DIVERSION BETWEEN TWO PAIRS OF ENTANGLED COHERENT STATES
Authors: PRAKASH H. , CHANDRA N. , PRAKASH R. , KUMAR SHIVANI A.
Published: August 2010

We propose a change in the scheme of Xin-Hua for entanglement diversion between two pairs of entangled coherent states using beam splitter, two-phase shifters, and photon counting measurements. We find that an almost perfect diversion of entanglement is possible if an appreciable mean number of photons are present.
ELECTRONIC AND THERMOELECTRIC PROPERTIES OF PURE AND ALLOYS In2O3 TRANSPARENT CONDUCTORS
Authors: HOSSEINI S. M. , ALIABAD H. A. RAHNAMAYE , KOMPANY A.
Published: August 2010

Electronic and thermoelectric properties of pure In 2 O 3 and In 1.5 T 0.5 O 3 ( T = Sc , Y ) alloys including the band gap, the electrical and thermal conductivity, Seebeck coefficient and figure of merit have been investigated using semi-classical Boltzmann transport theory. The calculated results indicated that substituting indium atoms by these dopants have a significant influence on the electronic properties of alloyed In 2 O 3 crystals. Substitution of Sc and Y atoms for In atoms increases the band gaps and Seebeck coefficient. The intrinsic relations between electronic structures and the transport performances of In 2 O 3 and its alloys with Sc and Y are also discussed.
STRONG VISIBLE UPCONVERSION IN RARE EARTH ION-DOPED NaYF4 CRYSTALS
Authors: PATEL DARAYAS , VANCE CALVIN , KING NEWTON , JESSUP MALCOLM , GREEN LEKARA , SARKISOV SERGEY
Published: August 2010

NaYF 4: Er 3+, Yb 3+ crystals were prepared by simple synthetic method. Under 980 nm laser excitation, 408 nm, 539 nm and 655 nm upconversion emissions were recorded. Laser power and signal intensities of the upconverted emissions were obtained to understand the upconversion mechanisms.
SPATIAL SOLITARY WAVES IN GENERALIZED NON-LOCAL NONLINEAR MEDIA
Authors: ZHONG WEI-PING , YANG ZHENG-PING
Published: August 2010

We introduce a very general self-trapped beam solution to the generalized non-local nonlinear Schrödinger equation in cylindrical coordinates, by combining superpositions of the known single accessible soliton solutions. Specific values of soliton parameters are selected as initial conditions and superpositions of the single soliton solutions in the highly non-local regime are launched into the non-local nonlinear medium with Gaussian response function, to obtain novel numerical solitary wave solutions. Novel solitary waves have been constructed that exhibit unique features whose intensity pattern is formed by various figures.
O-BAND MULTI-WAVELENGTH FIBER LASER
Authors: AHMAD H. , ZULKIFLI M. Z. , LATIF A. A. , HARUN S. W.
Published: August 2010

In this paper, we demonstrated a novel multi-wavelength fiber laser system operating in the O -band (1310 nm) region. The proposed O -band multi-wavelength fiber laser uses a 1 × 24 Arrayed Waveguide Grating to generate eight output channels simultaneously with a span width of 14.05 nm. In addition to this, the tunability of a single wavelength output is also demonstrated using a 1 × 16 AWG together with an optical channel selector. A Semiconductor Optical Amplifier (SOA) operating at 1310 nm is used as the gain medium to provide the spontaneous and stimulated emissions required for the laser operation. The fiber laser has a tuning range of 1301.26 nm to 1311.18 nm with 9.92 nm span and channel spacing of 0.7 nm.