bluuebunny/crossref_metadata_2025 huggingface dataset:
Iron‐saturated lactoferrin as a comitogenic substance for neonatal rat hepatocytes in primary culture
Authors: Kohno Y. , Shiraki K. , Mura T. , Ikawa S.
Published: April 2008

We studied the effect of lactoferrin on DNA synthesis in neonatal rat hepatocytes in primary culture to determine if this agent acts as a mitogen in human milk. Thymidine incorporation into the DNA of cultured hepatocytes stimulated by lactoferrin in the presence of insulin and human epidermal growth factor was examined. Iron‐saturated lactoferrin increased DNA synthesis of neonatal hepatocytes by 1.5 times and this potency was the same as that of insulin. It significantly enhanced the stimulatory effect of human epidermal growth factor plus insulin; DNA synthesis under these conditions was seven times that of control. Iron‐free lactoferrin did not affect DNA synthesis, nor did the exogenous addition of ferric ions. The enhancement of DNA synthesis by iron‐saturated lactoferrin was significant for neonatal hepatocytes, but not for adult hepatocytes. These results suggest that iron‐saturated lactoferrin, which itself had low mitogenic activity, is a co‐mitogenic substance for neonatal hepatocytes in vitro.
Ureaplusma ureulyticum in the cerebrospinal fluid of a premature infant
Authors: Hentschel J. , Abele‐Horn M. , Peters J.
Published: April 2008

A premature infant, born at 28 weeks' gestation, was found to be colonized with Ureaplasma urealyticum and developed intraventricular hemorrhage and progressive hydrocephalus during the first weeks of life. The organism was isolated from the infant's cerebrospinal fluid in the absence of marked cerebrospinal fluid pleocytosis, but meningitis was suspected on the basis of low glucose and high protein content. Since this organism was resistant to erythromycin by clinical criteria, the infant was treated with chloramphenicol for 20 days. Cerebrospinal fluid sterilization was demonstrated; hydrocephalus, however, was persistent and made intraventricular shunt placement necessary.
Predictors of delayed first voiding in newborn
Authors: Vuohelainen Tuomo , Ojala Riitta , Virtanen Anita , Holm Päivi , Tammela Outi
Published: April 2008

Aim: Delay >24 h of age in neonates' first voiding attracts attention, although the phenomenon is usually benign. Earlier studies indicate that stress increases the infant's arginine vasopressin (AVP) and aldosterone secretion during birth. Our aim was to seek predictors of delayed first voiding and indirect evidence of AVP effect behind this phenomenon.

Methods: The study population comprised 20 normal‐term newborns whose first voiding was delayed >24 h of age (cases), and 19 age‐matched control infants who voided for the first time at <24 h of age (controls). The first urine was collected and osmolality (U‐Osm) and sodium content (U‐Na) measured.

Results: The median of U‐osm in cases was 432.50 (284–519) and in controls 337.50 (169–497) mOsm/L (p = 0.005), and U‐Na 21.50 (9–241) and 40.00 (13–226) mmol/L (p = 0.001), respectively. Cases were more frequently born to primiparous mothers than controls (70% vs. 21%, p = 0.004). Duration of labour was longer in cases than controls, first stage 10.5 h (3.92–20.50 h) versus 5.7 h (1.17–16.00 h) (p = 0.045) and second stage 0.42 h (0.08–1.25 h) versus 0.17 h (0.08–0.92 h) (p = 0.015). All seven (35%) abnormal cardiotocographies were recorded with cases (p = 0.008).

Conclusions: Delayed voiding appears to be related to a prolonged and stressful birth. Laboratory findings in the first urine suggest increased AVP and aldosterone secretion in such cases.
Adenosine Actions are Preserved in Corpus Cavernosum from Obese and Type II Diabetic db/db Mouse
Authors: Carneiro Fernando Silva , Giachini Fernanda R.C. , Lima Victor V. , Carneiro Zidonia N. , Leite Romulo , Inscho Edward W. , Tostes Rita C. , Webb R. Clinton
Published: April 2008

Introduction

Erectile dysfunction (ED) in diabetes is associated with autonomic neuropathy and endothelial dysfunction. Whereas the nonadrenergic-noncholinergic (NANC)/neurogenic nitric oxide pathway has received great attention in diabetes-associated ED, few studies have addressed sympathetic overactivity.

Aim

To test the hypothesis that adenosine-induced inhibition of adrenergic-mediated contractile responses in mouse corpus cavernosum is impaired in the presence of diabetes.

Methods

The db/db (obesity and type II diabetes caused by a leptin receptor mutation) mouse strain was used as a model of obesity and type II diabetes, and standard procedures were performed to evaluate functional cavernosal responses.

Main Outcome Measures

Increased cavernosal responses to sympathetic stimulation in db/db mice are not associated with impaired prejunctional actions of adenosine.

Results

Electrical field stimulation (EFS)-, but not phenylephrine (PE)-, induced contractions are enhanced in cavernosal strips from db/db mice in comparison with those from lean littermates. Direct effects of adenosine, 2-chloro-adenosine, A1 receptor agonist C-8031 (N6 cyclopentyladenosine), and sodium nitroprusside are similar between the strips from lean and db/db mice, whereas relaxant responses to acetylcholine and NANC stimulation are significantly impaired in the cavernosal strips from db/db mice. 5′-Iodotubercidin (adenosine kinase inhibitor) and dipyridamole (inhibitor of adenosine transport), as well as the A1 agonist C-8031, significantly and similarly inhibit contractions induced by stimulation of adrenergic nerves in the cavernosal strips from lean and db/db mice.

Conclusions

Results from this study suggest that corpora cavernosa from obese and diabetic db/db mice display altered neural-mediated responses that would favor penile detumescence, i.e., increased contractile response to adrenergic nerve stimulation and decreased relaxant responses upon activation of NANC nerves. However, increased cavernosal responses to adrenergic nerve stimulation are not due to impaired negative modulation of sympathetic neurotransmission by adenosine in this diabetic model.
Does increased zinc uptake enhance grain zinc mass concentration in rice?
Authors: Jiang W. , Struik P.C. , Van Keulen H. , Zhao M. , Jin L.N. , Stomph T.J.
Published: April 2008

Rice (Oryza sativa) is the worlds’ most important cereal and potentially an important source of zinc (Zn) for people who eat mainly rice. To improve Zn delivery by rice, plant Zn uptake and internal allocation need to be better understood. This study reports on within‐plant allocation and potential Zn accumulation in the rice grain in four so‐called aerobic rice cultivars (Handao297, K150, Handao502 and Baxiludao). Two controlled‐condition experiments were carried out, one with a wide range of constant Zn concentrations in the medium and one with a range of plant growth rate‐related supply rates. In both experiments, increased Zn supply induced increased plant Zn uptake rate throughout crop development, when expressed as daily Zn uptake (μg day−1) or as daily Zn uptake per gram of plant dry matter (μg g−1). Zinc mass concentration (ZnMC) in all plant organs increased with an increase in Zn supply but to various degrees. At higher uptake levels, the ZnMC in stems increased most, while the ZnMC in hulled grains (brown rice) increased least. The increase in leaf ZnMC was generally small, but at toxic levels in the medium, leaf ZnMC increased significantly. It appears that regulation of grain Zn loading differs from regulation of Zn loading to other organs. A milling test on seeds of Baxiludao and Handao502 showed that when ZnMC in brown rice increased from 13 to 45 mg kg−1, ZnMC in polished rice grains (endosperm) also increased from 9 to 37 mg kg−1 but remained three to five times lower than that in the bran. Irrespective of the ZnMC in the brown rice, around 75% of total grain Zn was present in the endosperm. In both cultivars, there was a major difference in ZnMC between bran and endosperm (120 and 37 mg kg−1, respectively), suggesting a barrier for Zn transport between the two tissues. There seems to be a second barrier between stem and rachis, as their ZnMCs also differed greatly (300 and 100 mg kg−1, respectively) in both cultivars at higher plant ZnMC. It is concluded that there is too little scope from a human nutrition perspective to enhance ZnMC in rice endosperm by simply increasing the Zn supply to rice plants because Zn allocation to the endosperm is limited, while observed genotypic differences indicate scope for improvement through breeding.
IDENTIFICATION OF OXIDATION PRODUCTS OF 2,3,5,4′‐TETRAHYDROXYSTILBENE 2‐O‐β‐d‐GLUCOPYRANOSIDE FROM POLYGONUM MULTIFLORUM THUNB WITH H2O2
Authors: LV LI SHUANG , TANG JIAN , HO CHI‐TANG
Published: April 2008

The major stilbene glycoside, 2,3,5,4′‐tetrahydroxystilbene 2‐O‐β‐d‐glucopyranoside (PM‐SG), was purified from the ethanol extract of the roots of Polygonum multiflorum Thunb. In order to better understand the antioxidation mechanism of PM‐SG, PM‐SG was allowed to react with H2O2, and the reaction products were isolated by chromatography and identified by liquid chromatography–mass spectrometry and nuclear magnetic resonance. The formation of a major product, a dimer of PM‐SG, indicated that the C5 phenolic group on PM‐SG was more reactive toward the hydrogen abstraction.

PRACTICAL APPLICATIONS

The root of Polygonum multiflorum Thunb is an important medicinal plant and has been used for over several thousand years in China. A major stilbene glucoside, 2,3,5,4′‐tetrahydroxystilbene 2‐O‐β‐d‐glucopyranoside (PM‐SG) is known as the active antioxidant of this plant material. In the present study, structural determination of the oxidation products from the reaction of PM‐SG with H2O2 was carried out in order to allow better understanding of the antioxidant mechanism of this compound.
QUALITY OF BREAD SUPPLEMENTED WITH POPPED AMARANTHUS CRUENTUS GRAIN
Authors: BODROŽA‐SOLAROV MARIJA , FILIPČEV BOJANA , KEVREŠAN ŽARKO , MANDIĆ ANAMARIJA , ŠIMURINA OLIVERA
Published: April 2008

The addition of popped Amaranthus cruentus grain to wheat bread formulation at 10, 15 and 20% levels (flour basis) was carried out to test the effects on sensory and nutritional characteristics of the supplemented bread samples. The addition of popped amaranth grain increased ash, protein and crude fiber content significantly. Zinc content increased by 42.6–74.6%, manganese content by 51.7–90.8%, magnesium content by 75.7–88.0% and calcium content by 57–171% in the supplementation ranges from 10 to 20% of popped amaranth grain. Bread samples supplemented with popped grains had a significantly higher content of squalene in comparison with the control sample (8–12 times higher). Loaf volume of supplemented bread samples decreased from 3.54 to 2.36 mL/g. Also, a significant increase in crumb hardness and lower crumb elasticity was observed. The supplementation contributed to denser crumb structure, more uniform porosity, improved crust color and flavor. It might be concluded that supplementation levels up to 15% (flour basis) were sensorially acceptable.

PRACTICAL APPLICATIONS

Bread made from refined wheat flour, besides being a good source of energy, is considered to be nutritionally poor. Therefore, the addition of inexpensive staples with superior nutritional quality such as some pulses, cereals or pseudocereals to wheat flour could improve the nutritional quality of wheat products. Amaranth is a pseudocereal that contains high levels of fat, dietary fibers, lysine and minerals, especially calcium and magnesium. The addition of amaranth grain to wheat bread contributes to higher intakes of proteins, fibers, fat and minerals. The usage of popped amaranth grain is advantageous because it excludes the need for grain milling and the necessity for preparative steps before mixing in bakeries. In addition, thermal treatment increases the protein efficiency ratio and gelatinizes starch that affects positively the stability, strength and freshness of the crumb. Popped amaranth grain also contributes to the pleasant taste and overall acceptability of supplemented bread.
Tectonic Influences on Ground Water Quality: Insight from Complementary Methods
Authors: Earman Sam , McPherson Brian J.O.L. , Phillips Fred M. , Ralser Steve , Herrin James M. , Broska James
Published: April 2008

A study using multiple techniques provided insight into tectonic influences on ground water systems; the results can help to understand ground water systems in the tectonically active western United States and other parts of the world. Ground water in the San Bernardino Valley (Arizona, United States and Sonora, Mexico) is the main source of water for domestic use, cattle ranching (the primary industry), and the preservation of threatened and endangered species. To improve the understanding of ground water occurrence, movement, and sustainability, an investigation was conducted using a number of complementary methods, including major ion geochemistry, isotope hydrology, analysis of gases dissolved in ground water, aquifer testing, geophysics, and an examination of surface and subsurface geology. By combining information from multiple lines of investigation, a more complete picture of the basin hydrogeology was assembled than would have been possible using fewer methods. The results show that the hydrogeology of the San Bernardino Valley is markedly different than that of its four neighboring basins in the United States. The differences include water quality, chemical evolution, storage, and residence time. The differences result from the locally unique geology of the San Bernardino Valley, which is due to the presence of a magmatically active accommodation zone (a zone separating two regions of normal faults with opposite dips). The geological differences and the resultant hydrological differences between the San Bernardino Valley and its neighboring basins may serve as a model for the distinctive nature of chemical evolution of ground water in other basins with locally distinct tectonic histories.
Ardhanār?śvara: What We Know and What We Do not
Authors: Goldberg Ellen
Published: April 2008

Ardhanār?śvara is an expression of malebrahmanicalorthodox discourse; yet, this fact does not dismiss or negate the primary role that Ardhanār?śvara plays as a symbol of wholeness and liberation within Indian religion. We know by looking at the image of Ardhanār?śvara that although Pārvat? is placed on the left hand side, she constitutes no less than half of Śiva's body. In other words, Ardhanār?śvara is as much female as he or she is male. Consequently, even though we see the anthropomorphic body of Ardhanār?śvara idealized by the patriarchal norms of sacred iconographic convention, we also recognize profound attempts at symmetry, complementarity, and wholeness. In this state‐of‐the‐field review, we look at both of these areas to establish what we know, and what we do not know, about Ardhanār?śvara.
Religious Maintenance and Adaptation: An Example from the South Australian Hindu Diaspora
Authors: Foster Heather
Published: April 2008

Raymond Williams in A Sacred Thread: Modern Transmission of Hindu Traditions in India and Abroad (1992) identified different strategies within Hindu communities outside India, specifically in the USA, which enabled adaptation to the host community to occur while maintaining (and adjusting) religious beliefs and practices within the diaspora. J. R. Hinnells subsequently proposed ten factors for change and continuity in diaspora religion. These approaches form a useful analytical tool for understanding the manner in which Hinduism has developed, and is developing, in South Australia. This article examines the development of diaspora Hinduism in the Australian cities of Adelaide and Whyalla, in the light of both Williams’ and Hinnells’ categories. A comparison of the strategies of the smaller Whyalla community is juxtaposed against the more developed and larger Adelaide Hindu community, highlighting the similarities and differences between distinctive communities in different circumstances. Scholarship by Williams and Hinnells is useful in providing a framework for understanding the developments within these communities in Australia.
Time‐resolved Singlet Oxygen Phosphorescence Measurements from Photosensitized Experiments in Single Cells: Effects of Oxygen Diffusion and Oxygen Concentration
Authors: Hatz Sonja , Poulsen Lars , Ogilby Peter R.
Published: April 2008

Time‐resolved singlet oxygen, O2(a1Δg), phosphorescence experiments have been performed in single cells upon pulsed laser irradiation of a photosensitizer incorporated into the cell. Data recorded as a function of the partial pressure of ambient oxygen to which the cell is exposed reflect apparent values for the intracellular oxygen diffusion coefficient and intracellular oxygen concentration that are smaller than those found in neat H2O. This conclusion is supported by O2(a1Δg) phosphorescence data and sensitizer triplet state absorption data recorded in control experiments on sucrose solutions with different viscosities. We recently demonstrated that the intracellular lifetime of O2(a1Δg) is comparatively long (∼3 μs) and does not differ significantly from that in neat H2O (∼3.5 μs). Despite this long lifetime, however, our estimate of an apparent intracellular oxygen diffusion coefficient in the range ∼2–4 × 10−6 cm2 s−1 means that the spatial domain of intracellular O2(a1Δg) activity will likely have a spherical radius of ∼100 nm. This latter point helps reconcile seeming inconsistencies between our direct O2(a1Δg) lifetime data and results obtained from independent photobleaching experiments that show a limited translational diffusion distance for O2(a1Δg) within a cell.
Data integration across borders: a case study of the Abbotsford‐Sumas aquifer (British Columbia/Washington State)1
Authors: Schuurman Nadine , Deshpande Aparna , Allen Diana M.
Published: April 2008

Abstract:  Integrating spatial datasets from diverse sources is essential for cross‐border environmental investigations and decision‐making. This is a little investigated topic that has profound implications for the availability and reliability of spatial data. At present, ground‐water hydrostratigraphic models exist for both the Canadian or for the United States (U.S.) portion of the aquifer but few are integrated across the border. In this paper, we describe the challenges of integrating multiple source, large datasets for development of a ground‐water hydrostratigraphic model for the Abbotsford‐Sumas Aquifer. Growing concerns in Canada regarding excessive withdrawal south of the border and in the U.S. regarding nitrate contamination originating north of the border make this particular aquifer one of international interest. While much emphasis in GIScience is on theoretical solutions to data integration, such as current ontology research, this study addresses pragmatic ways of integrating data across borders. Numerous interoperability challenges including the availability of data, metadata, data formats and quality, database structure, semantics, policies, and cooperation are identified as inhibitors of data integration for cross‐border studies. The final section of the paper outlines two possible solutions for standardizing classification schemes for ground‐water models – once data heterogeneity has been addressed.
Phase II study of hepatic arterial infusion of a fine‐powder formulation of cisplatin for advanced hepatocellular carcinoma
Authors: Yoshikawa Masaharu , Ono Naofumi , Yodono Hiraku , Ichida Takafumi , Nakamura Hironobu
Published: April 2008

Aim:  Intra‐arterial cisplatin appears to have high therapeutic efficacy, but this has not been studied in detail. Accordingly, we developed a fine‐powder cisplatin formulation and tested it in advanced hepatocellular carcinoma (HCC) patients in an open‐label, uncontrolled study in which 27 institutions participated.

Methods:  The patients in this study had inoperable advanced HCC without extrahepatic metastases. All received two infusions of high‐concentration cisplatin (1.43 mg/mL) via the hepatic artery at a dose of 65 mg/m2, with an intervening 4–6 week interval.

Results:  Cisplatin efficacy and safety were assessed in 80 patients. We found partial responses in 27 cases, no change in 37, and progressive disease in 11 (five were not evaluated). The overall response rate was 33.8%. The 1‐year survival rate was 67.5% and the 2‐year survival rate was 50.8%. Severe adverse effects (≥grade 3) included anorexia in 22.5%, vomiting in 6.3%, abdominal pain in 1.3%, thrombocytopenia in 25%, neutropenia in 13%, leukopenia in 1.3%, hypochromia in 1.3%, elevated serum aspartate aminotransferase in 32.5%, elevated serum alanine aminotransferase in 11.3%, elevated serum bilirubin in 3.8%, decreased serum albumin in 1.3%, elevated serum alkaline phosphatase in 1.3%, elevated γ‐glutamyltranspeptidase in 3.8%, and elevated serum creatinine in 2.5%. Death from myocardial infarction occurred as an incidental event in one case, and no other life‐threatening, adverse events were observed.

Conclusion:  Although intra‐arterial cisplatin has substantial local and systemic toxicity, high therapeutic efficacy suggests the potential usefulness of this agent in the treatment of advanced HCC.
Sequential Linearization as an Approach to Real-Time Marine Gas Turbine Simulation
Authors: Smith D. L. , Stammetti V. A.
Published: April 2008

A real-time marine gas turbine simulation would offer an essential basis for advanced marine propulsion control designs. Such designs may be realized as model reference controllers and/or health monitoring controllers. This paper presents an approach to real-time turbine simulation, using a method of sequential state space linearizations. The linearizations are shown to be simple enough to be computed in real time. Comparisons between simulations and experiments are presented and discussed. The approach is shown to have very good accuracy for both transient and steady-state predictions.
Propulsion Systems for Supersonic V/STOL Aircraft
Authors: Lewis W. J.
Published: April 2008

A number of different powerplant systems have been and are being considered for supersonic V/STOL aircraft. Some of the main features of these different powerplants are described. As a result of studying the results of operation of successful and unsuccessful V/STOL aircraft in the powered lift condition, a number of real requirements for practical and flexible operation can be identified. These requirements may have a profound impact on the design and configuration of the powered lift powerplant. Some of these are discussed and conclusions reached.
Desktop Failure Analysis on a Microcomputer Using Weibull, Lognormal, and Renewal Data
Authors: Byers J. L.
Published: April 2008

Gas turbine components and parts are widely known to have many failure modes for which the failures correlate in either the Weibull or Lognormal probability distributions. This paper describes a typical case, which is handled by the new computer programs now being used by the U. S. Navy. These programs have brought the capability to make such analyses directly to the designer or analyst’s desk instead of having to be sent off to a central computer to wait in line. The programs are interactive with the user and extremely user friendly. Uses are expanding to cover almost every area in the life cycle of gas turbines where it would be beneficial to forecast future failures. This makes the programs useful to managers, logisticians, life cycle cost analysts, and a host of others. Wide applicability of the methods assures usage outside of the gas turbine field.
Development of an Integrated BEM for Hot Fluid-Structure Interaction
Authors: Dargush G. F. , Banerjee P. K.
Published: April 2008

A boundary element approach is developed for problems of hot fluid-structure interaction. The structure is idealized as a thermoelastic solid, and a time-domain, boundary-only integral formulation is described. Meanwhile, several approaches are discussed for the hot fluid. Integral equations are developed for both compressible and incompressible thermoviscous flow. Due to the presence of nonlinear convective terms in the governing differential equations, domain discretization is generally required. However, with the introduction of reference velocities, volume modeling often can be confined to regions near obstacles and walls. All formulations are implemented for two-dimensional problems in GP-BEST, a general purpose boundary element computer program. An overview of this numerical implementation is provided, along with several illustrative examples. The present fluid formulations are appropriate in the low to medium Reynolds number ranges; however, some enhancements required for higher speed simulations are noted.
Probabilistic Structural Analysis for Advanced Space Propulsion Systems
Authors: Cruse T. A. , Unruh J. F. , Wu Y.-T. , Harren S. V.
Published: April 2008

This paper reports on recent extensions to ongoing research into probabilistic structural analysis modeling of advanced space propulsion system hardware. The advances concern probabilistic dynamic loading, and probabilistic nonlinear material behavior. In both cases, the reported work represents a significant advance in the state-of-the-art for these topics. Random, or probabilistic loading is normally concerned with the loading described in power spectral density (PSD) terms. The current work describes a method for incorporating random PSD’s along with random material properties, damping, and structural geometry. The probabilistic material response is concerned with the prediction of nonlinear stress-strain behavior for physical processes that can be linked to the original microstructure of the material. Such variables as grain size and orientation, grain boundary strength, etc., are treated as random, initial variables in generating stochastic stress-strain curves. The methodology is demonstrated for a creep simulation.
Unbalance Response of a Jeffcott Rotor Incorporating Short Squeeze Film Dampers
Authors: El-Shafei A.
Published: April 2008

The steady-state unbalance response of a Jeffcott rotor incorporating short squeeze film dampers executing circular centered whirl is obtained by a fast algorithm. Savings in execution time of the order of fifty times are gained over numerical integration. Fluid inertia forces are included in the model of the squeeze film dampers. The fast algorithm allows parametric studies to be performed. It is shown that fluid inertia results in the excitation of a second mode for the Jeffcott rotor, decreases the possibility of jump resonance, and decreases the useful range of vibration isolation of the dampers. It is also shown that a squeeze film damper with no centering spring (or a very soft spring) may be advantageous with regards to the unbalance response and the vibration isolation capability of the dampers.
Optimum Weight Design of a Rotor Bearing System With Dynamic Behavior Constraints
Authors: Shiau Ting Nung , Hwang Jon Li
Published: April 2008

An efficient design algorithm for optimum weight design of a rotor bearing system with dynamic behavior constraints is investigated. The constraints include restrictions on stresses, unbalance response, and/or critical speeds. The system dynamic behaviors are analyzed by the finite element method. The exterior penalty function method is used as the optimization technique to minimize the system weight. The system design variables are the cross-sectional areas of the shaft and the stiffnesses of the bearings. The sensitivity analysis of the system parameters is also investigated. The example of a single spool rotor bearing system is employed to demonstrate the merits of the design algorithm with different combinations of dynamic behavior constraints. At the optimum stage, it is shown that the weight of the rotor system can be significantly reduced. Moreover, the optimum design weights are quite different for various combinations of dynamic behavior constraints.
Effective Tools for Diagnosing Elusive Turbomachinery Dynamics Problems in the Field
Authors: Simmons H. R. , Smalley A. J.
Published: April 2008

This paper describes and discusses techniques that can effectively diagnose dynamics problems in turbomachinery. A variety of elusive dynamics problems are identified that require definition, quantification, diagnosis, and monitoring. The state of the art in measurement and signal processing techniques is discussed with reference to such factors as the directness of the measurement, the degree of intrusion required, the difficulty of installation, and the reliability or durability of the sensor. Several examples of techniques are provided that have proved to be effective in diagnosing elusive dynamics problems; some examples allow comparison of alternative techniques with different degrees of effectiveness. Problems addressed include rotating stall in the compressor section of a gas turbine, coupled lateral/torsional vibration in a gas turbine driven pipeline compressor, forced vibration of combustor parts, strain gage telemetry of blade vibrations, and nonintrusive measurement of blade vibrations using bearing-mounted accelerometers.
A Solution for the Temperature Distribution in a Pipe Wall Subjected to Internally Stratified Flow
Authors: Smith W. R. , Cassell D. S. , Schlereth E. P.
Published: April 2008

Stratified flow in a pipe is a phenomenon in which two distinct fluids flow simultaneously through a pipe with little or no mixing. Under certain conditions the flow stratification will result in a dramatic temperature variation within the pipe wall. This paper presents a solution for the temperature distribution in a pipe wall subjected to internally stratified flow by solving Laplace’s equation in cylindrical coordinates using a finite Fourier cosine transform. The top and bottom sections are treated separately and coupled by boundary conditions at the interface. A one-dimensional approximation for the temperature distribution in the pipe at the interface is developed to uncouple the top and bottom sections, thereby avoiding the necessity for simultaneous solution of two partial differential equations. Results from the solution for a case study of a particular physical situation were compared to the solution obtained using the ANSYS finite element computer program. The solution agreed with the finite element solution to within approximately 2.4 percent throughout the pipe wall and was within 0.4 percent for most of the pipe.
A Turbocharger for the 1990s
Authors: Johnson E. R.
Published: April 2008

The large-bore engines of the 1970s and 1980s have seen tremendous amounts of technological improvements. The key buzzwords were: “Lower the emissions, and improve the fuel consumption.” As we move into the 1990s, we see dramatic improvements in specific outputs along with continued research to further improve emissions and fuel consumption. One of the keys to success will have to be the degree to which the industry responds with improvements in turbocharger performance. In 1985, Cooper Bessemer Rotating Products Division began a program to develop the turbocharger of the 1990s. This paper will describe the development of the CB turbocharger series from concept to early production.
A Comparative Study of the Stiller-Smith and Slider-Crank Mechanisms for Eight-Cylinder Internal Combustion Engine Use
Authors: Smith J. E. , Smith J. C. , McKisic A. D.
Published: April 2008

Of the possible alternatives to the slider-crank for internal combustion engine use, the Scotch yoke in its various forms and inversions has received considerable attention. Among these, the Stiller-Smith mechanism has shown promise as being a viable option. Kinetostatic models were formulated to determine loading within similar eight-cylinder, four-stroke, compression-ignition engines with emphasis placed on comparing the number and similarity of mechanism components, implications of component and linkage motions, the loading experienced by similar bearing surfaces, and the friction losses of specific components.
Shop Test of the 501F—A 150 MW Combustion Turbine
Authors: Entenmann D. T. , North W. E. , Fukue I. , Muyama A.
Published: April 2008

The 501F is a 150 MW-class 60 Hz engine jointly developed by Westinghouse Electric Corporation and Mitsubishi Heavy Industries, Ltd. This paper describes the full-load shop test program for the prototype engine, as carried out in Takasago, Japan. The shop test included a full range of operating conditions, from startup through full load at the 1260°C (2300°F) design turbine inlet temperature. The engine was prepared with more than 1500 instrumentation points to monitor flow path characteristics, metal temperatures, displacements, pressures, cooling circuit characteristics, strains, sound pressure levels, and exhaust emissions. The results of this shop test indicate the new 501F engine design and development effort to be highly successful. The engine exceeds power and overall efficiency expectations, thus verifying the new concepts and design improvements.
Steady-State Analysis of a Nonlinear Rotor-Housing System
Authors: Kim Y. B. , Noah S. T.
Published: April 2008

The periodic steady-state response of a high-pressure oxygen turbopump (HPOTP) of a space shuttle main engine (SSME), involving a clearance between the bearing and housing carrier, is sought. A harmonic balance method utilizing Fast Fourier Transform (FFT) algorithm is developed for the analysis. An impedance method is used to reduce the number of degrees of freedom to the displacements at the bearing clearance. Harmonic and subharmonic responses to imbalance for various system parameters are studied. The results show that the computational technique developed in this study is an effective and flexible method for determining the stable and unstable periodic response of complex rotor-housing systems with clearance-type nonlinearity.
Corrosion and Degradation of Ceramic Particulate Filters in Direct Coal-Fired Turbine Applications
Authors: Sawyer J. , Vass R. J. , Brown N. R. , Brown J. J.
Published: April 2008

High-temperature ceramic filters show considerable promise for efficient particulate removal from coal combustion systems. Advanced coal utilization processes such as direct coal-fired turbines require particulate-free gas for successful operation. This paper describes the various ceramic particulate filters under development and reviews the degradation mechanisms expected when operated in coal combustion systems.
Design of Ceramic Gas Turbine Components
Authors: Stu¨rmer G. , Fundus M. , Schulz A. , Wittig S.
Published: April 2008

At the Institute for Thermal Turbomachinery (ITS), University of Karlsruhe, detailed theoretical and experimental studies concerning ceramic gas turbine components have been performed. For the analysis of the reliability of ceramic components by finite element calculations, the numerical code CERITS has been developed, which follows a strategy similar to that suggested by Gyekenyesi. CERITS determines the failure probability of ceramic components with reference to volumetric flaws. Different fracture criteria can be considered. CERITS is coupled to the finite element code ADINA, which facilitates the prediction of the required temperature and stress distributions. The procedure is demonstrated utilizing gas turbine combustor components.
Design and Development of a Research Combustor for Lean Blow-Out Studies
Authors: Sturgess G. J. , Sloan D. G. , Lesmerises A. L. , Heneghan S. P. , Ballal D. R.
Published: April 2008

In a modern aircraft gas turbine combustor, the phenomenon of lean blow-out (LBO) is of major concern. To understand the physical processes involved in LBO, a research combustor was designed and developed specifically to reproduce recirculation patterns and LBO processes that occur in a real gas turbine combustor. A total of eight leading design criteria were established for the research combustor. This paper discusses the combustor design constraints, aerothermochemical design, choice of combustor configurations, combustor sizing, mechanical design, combustor light-off, and combustor acoustic considerations that went into the final design and fabrication. Tests on this combustor reveal a complex sequence of events such as flame lift-off, intermittency, and onset of axial flame instability leading to lean blowout. The combustor operates satisfactorily and is yielding benchmark quality data for validating and refining computer models for predicting LBO in real engine combustors.
Turbulent Combustion Properties Behind a Confined Conical Stabilizer
Authors: Pan J. C. , Schmoll W. J. , Ballal D. R.
Published: April 2008

Turbulence properties were investigated in and around the recirculation zone produced by a 45 deg conical flame stabilizer of 25 percent blockage ratio confined in a pipe supplied with a turbulent premixed methane-air mixture at a Reynolds number of 5.7×104. A three-component LDA system was used for measuring mean velocities, turbulence intensities, Reynolds stresses, skewness, kurtosis, and turbulent kinetic energy. It was found that wall confinement elongates the recirculation zone by accelerating the flow and narrows it by preventing mean streamline curvature. For confined flames, turbulence production is mainly due to shear stress-mean strain interaction. In the region of maximum recirculation zone width and around the stagnation point, the outer stretched flame resembles a normal mixing layer and gradient-diffusion closure for velocity holds. However, and in the absence of turbulent heat flux data, countergradient diffusion cannot be ruled out. Finally, and because of the suppression of mean streamline curvature by confinement, in combusting flow, the production of turbulence is only up to 33 percent of its damping due to dilatation and dissipation.
The Effect of Swirl on the Velocity and Turbulence Fields of a Liquid Spray
Authors: Bren˜a de la Rosa A. , Wang G. , Bachalo W. D.
Published: April 2008

The work reports an experimental study of the effect of swirl on the structure of a liquid spray, i.e., on the behavior of drops and their interaction with the gaseous phase, and on the velocity and turbulence fields of the spray in the swirling flow. Three vane-type swirlers having low, medium, and high swirl numbers were used in the tests. The swirlers were placed on the liquid supply tube of a pressure atomizer and tested in the wind tunnel under specified conditions. Properties of the dispersed phase such as velocity and size distributions, particle number density, and volume flux were measured at several locations within the swirling flow field. In addition, mean velocity and turbulence properties were obtained for the gas phase. The results show that flow reversal of the drops is present at the high swirl number within the recirculation region. The spatial distribution of drops reveals a widening of the spray with increasing swirl strength while the concentration of large drops is shown to increase near the core of the swirling field with increasing swirl number. Plots of the turbulence kinetic energy, normal Reynolds stresses, and Reynolds shear stresses show double-peak radial distributions, which indicate regions in the flow where high energy content, mean velocity gradients, and large shear forces are present. The decay of turbulence velocities in the axial direction was observed to be very fast, an indication of high diffusion and dissipation rates of the kinetic energy of turbulence. The significance of the turbulence measurements is that these double-peak profiles indicate a deviation of the swirling spray from isotropy. This information should be relevant to researchers modeling these complex flows.
Factors Influencing the Effective Spray Cone Angle of Pressure-Swirl Atomizers
Authors: Chen S. K. , Lefebvre A. H. , Rollbuhler J.
Published: April 2008

The spray cone angles produced by several simplex pressure-swirl nozzles are examined using three liquids whose viscosities range from 0.001 to 0.012 kg/ms (1 to 12 cp). Measurements of both the visible spray cone angle and the effective spray cone angle are carried out over wide ranges of injection pressure and for five different values of the discharge orifice length/diameter ratio. The influence of the number of swirl chamber feed slots on spray cone angle is also examined. The results show that the spray cone angle widens with increase in injection pressure but is reduced by increases in liquid viscosity and/or discharge orifice length/diameter ratio. Variation in the number of swirl chamber feed slots between one and three has little effect on the effective spray cone angle.
Design and Performance of a Small-Power Clausius-Rankine Process
Authors: Shao Z. , Malobabic M. , Burhorn D. , Rautenberg M.
Published: April 2008

In recent years, an increasing awareness of the shortness of raw materials has led to an improved utilization of the energy input in thermal processes. Utilization of the heat generated in such processes and machinery can improve the overall efficiency of the latter and converse raw materials. In particular, combustion engines have a poor overall efficiency due to the high-temperature exhaust gases they produce. The classical Clausius-Rankine process can be applied to such machines in order to utilize the heat generated so as to provide turbocharging of the latter. The design of such a Clausius-Rankine process in connection with a newly developed steam turbine based upon the Pelton principle is presented. In this design, particular value is placed upon the small size of individual units and a comparability with actual thermodynamic conditions in combustion engines.
Comparative Thermodynamics for Brayton and Rankine Cycles
Authors: Beans E. W.
Published: April 2008

The thermal efficiency, work per unit mass, and work per unit volume of the simple Rankine and Brayton cycles are expressed in terms of seven independent variables using a simplified thermodynamic model. By requiring equal efficiency, equal work conditions, and the same maximum cycle temperature for both cycles, two necessary relationships are established between the seven independent variables. These two relationships along with two maximum work conditions produce a method for comparing required and selected properties. These comparisons provide useful guidelines for the selection of the cycle and cycle fluids. The comparison analysis shows that for a given application the more attractive cycle is strongly dependent upon the fluids selected.
Physical Aspects of Deposition From Coal-Water Fuels Under Gas Turbine Conditions
Authors: Wenglarz R. A. , Fox R. G.
Published: April 2008

Deposition, erosion, and corrosion (DEC) experiments were conducted using three coal-water fuels (CWF) in a staged subscale turbine combustor operated at conditions of a recuperated turbine. This rich-quench-lean (RQL) combustor appears promising for reducing NOx levels to acceptable levels for future turbines operating with CWF. Specimens were exposed in two test sections to the combustion products from the RQL combustor. The gas and most surface temperatures in the first and second test sections represented temperatures in the first stators and rotors, respectively, of a recuperated turbine. The test results indicate deposition is affected substantially by gas temperature, surface temperature, and unburned carbon due to incomplete combustion. The high rates of deposition observed at first stator conditions showed the need for additional tests to identify CWF coals with lower deposition tendencies and to explore deposition control measures such as hot gas cleanup.
Investigation and Computer Simulation of Diesel Injection System With Rotative Pump
Authors: Ficarella A. , Laforgia D. , Cipolla G.
Published: April 2008

The behavior of an injection system with a rotative pump for reciprocating engines has been investigated. Experimental investigations were carried out using a specially designed apparatus to monitor several parameters, such as pressure inside the different chambers of the apparatus, moving part lift, and injected fuel quantity. In addition, a predictive mathematical model, based on mass momentum conservation laws, was developed to simulate such behavior and to predict all the most important parameters of the injection system. The comparison between numerical and experimental results has been satisfactory, allowing a generalization of the model and extensive theoretical predictions of the system behavior.
Valve Event Optimization in a Spark-Ignition Engine
Authors: Assanis D. N. , Polishak M.
Published: April 2008

A computer simulation has been modified to study the effects of valve event parameters (lift, duration, and phasing) on spark-ignition engine performance. The zero-dimensional model employs polynomial and dynamic techniques to generate cam profiles for valve event optimization. The model was calibrated and validated against data from a General Motors 2.5-liter engine. The simulation was then used to determine optimum valve events under different engine conditions. This insight was used to improve the cam design. Subsequent engine testing confirmed that a 3 percent improvement in peak torque could be obtained with the optimized cam.
Combustion of Coal-Water Slurry in a Two-Cycle Diesel Engine: Effects of Fuel Amount and Timing
Authors: Uzkan T. , Horton C. E.
Published: April 2008

Coal-water slurry having micronized coal particles with approximately 50 percent coal loading is successfully ignited and combusted in one cylinder of a two-cylinder 645 EMD engine by using diesel fuel pilot ignition aid. The effects of three different parameters, namely, (a) pilot timing, (b) pilot amount, and (c) CWS fuel amount, are investigated in detail. The physical trends of combustion under single parametric variations are presented in terms of the cylinder pressure, temperature, heat release rates, and cumulative heat release curves. CWS combustion with less than 5 percent of the energy of combustion coming from pilot fuel is achieved.
The Influence of the Recirculation Region: A Comparison of the Convective Heat Transfer Downstream of a Backward-Facing Step and Behind a Jet in a Crossflow
Authors: Scherer V. , Wittig S.
Published: April 2008

Convective heat transfer is examined in two typical examples of separated flows, namely, the flow over a backward-facing step and a two-dimensional jet entering a crossflow. Local Nusselt numbers were determined in and behind the recirculation region. The main parameters influencing the heat transfer, the Reynolds number, and the momentum flux ratio of the jet and the crossflow have been varied over a wide range. In addition to heat transfer measurements, the flow field has been documented using an LDA system and oil film technique. The static pressure distribution at the wall within the separated flow is also given. The measurements are compared with the results of a numerical code, based on a finite volume method, where the well known k-ε model is employed. The differences in Nusselt numbers predicted with one- and two-layer models are shown to demonstrate the influence of wall functions on heat transfer. The numerical and experimental results are compared with available data, and the differences and similarities in the heat transfer behavior of separated flows are discussed.
EJ200—The Engine for the New European Fighter Aircraft
Authors: Lane R. J. , Behenna J.
Published: April 2008

This paper describes the concept and design of the EJ200 engine to meet the air staff targets for the European Fighter Aircraft. The international collaborative arrangements to support the program are shown and the lessons learned from previous collaboration illustrated. The excellent progress made in the program during the first year since the signing of the development contract is described to illustrate confidence in the ability to meet the design targets within the program time scales.