bluuebunny/crossref_metadata_2025 huggingface dataset:
The East Asian Way—With Air Conditioning
Authors: Yew Lee Kuan
Published: October 2009

Though the founding father of a tiny country on the tip of the Malay peninsula, Lee Kuan Yew is one of the giants of the arriving Asian century. Fifty years from now monuments will commemorate the legendary feats of this British‐trained barrister who only learned Chinese when he became prime minister in 1959. Not only did he miraculously transform the impoverished colonial entrepot of Singapore, rife with drugs and prostitution, into a gleaming model city state of the 21st century; his practical vision of soft‐authoritarian capitalism also became the template for Deng Xiaoping's “opening up and reform” in China, laying the basis for the stunning rise of a prosperous East Asia.

We met twice, in 1992 and 1995, in steamy Singapore, sitting in the icily air‐conditioned salon at Istana, the former British governor's residence, looking out over the manicured lawns, as we delved deep into the conflicts and complementarities of Confucian communitarianism and Western individualism. We met one last time in a snowbound chalet in Davos, Switzerland, in 1999 after his formal retirement as “senior minister” and graduation to “minister mentor,” the sage behind the throne.
How Many Casualties Are Too Many? Proportional Reasoning in the Valuation of Military and Civilian Lives1
Authors: Friedrich James , Dood Tiffany L.
Published: October 2009

People frequently judge saved lives as less valuable and deaths more acceptable when they are characterized as small fractions of larger “at‐risk” groups. Two studies with U.S. college students demonstrated this effect in judgments concerning acceptable numbers of U.S. military and Middle Eastern civilian casualties. At the beginning of the current U.S.–Iraq conflict (Study 1), priming cost–benefit reasoning produced greater proportional devaluation for Iraqi civilian than for U.S. military lives. In a hypothetical armed intervention in Iran to halt weapons development (Study 2), women but not men showed greater proportional devaluation for U.S. military than for Iranian civilian lives. In both studies, proportional reasoners were willing to accept more casualties. Implications for public perceptions and attitudes are discussed.
Music as an Unconditioned Stimulus: Positive and Negative Effects of Country Music on Implicit Attitudes, Explicit Attitudes, and Brand Choice1
Authors: Redker Christopher M. , Gibson Bryan
Published: October 2009

An experiment (N = 68) explored how background music in a realistic web advertisement could condition implicit and explicit attitudes toward a novel brand. Conditioning effects were apparent in both traditional explicit attitude measures and also in the Implicit Association Test (IAT). Further, brand choice was predicted by explicit attitudes, but prediction improved significantly when implicit attitudes were considered. Mood‐congruent judgment, demand effects, and conditioning are considered as potential explanations for our results, and we argue that conditioning provides the most parsimonious explanation. Finally, the results are discussed within the context of the associative‐propositional evaluation model (Gawronski & Bodenhausen, 2006). This model provides a framework for the integration of the implicit attitude construct into the study of consumer behavior.
Asian Risk Seeking and Overconfidence1
Authors: Li Shu , Bi Yan‐Ling , Zhang Yuching
Published: October 2009

Weber & Hsee (1998) proposed the “cushion effect” as an explanation of the higher risk taking observed in some East Asian samples, relative to Western samples. Yates, Lee, & Shinotsuka (1992) proposed that the overconfidence observed in most Asian countries, relative to Western countries, reflects differences in the number of arguments typically recruited in those countries. This study examined the 2 seemingly separated domains of research: risk taking and overconfidence. It compared individual and collective (both family and group) decisions among Chinese in Singapore. This permitted tests of both the cushion and the argument recruitment hypotheses. The overall results obtained no support for the cushion effect and partial support for the argument recruitment hypotheses.
Who trades water allocations? Evidence of the characteristics of early adopters in the Goulburn–Murray Irrigation District, Australia 1998–1999**
Authors: Wheeler Sarah , Bjornlund Henning , Shanahan Martin , Zuo Alec
Published: October 2009

This article applies a model of innovation to analyze the characteristics of irrigators within the Goulburn–Murray Irrigation District in Australia and examines the efficiency of the early water market in the late 1990s. Using multinominal and binary logit analyses we identify the factors associated with irrigators who sold or bought water allocations during 1998–1999 and irrigators who at that time had never participated in any kind of water trading. Contrary to expectations we find that early adopters of water trading were older farmers with low farm productivity, but that in line with theory they had higher levels of education, had spent less time farming, had larger irrigated area, farm operating surplus and farm assets, owned farms that were more intensively farmed, and were more progressive in their planning. There was only weak evidence to suggest that water moved from lower value uses to higher value uses, suggesting the water allocation market had limited efficiency in its’ initial years.
Nutrient consumption and household income in rural Mexico
Authors: Skoufias Emmanuel , Di Maro Vincenzo , González‐Cossío Teresa , Ramírez Sonia Rodríguez
Published: October 2009

We estimate the income elasticity for a variety of macro‐ and micronutrients using a sample of poor rural households in Mexico. The nutrient‐income elasticity is estimated using both parametric and semiparametric methods. A special focus is placed on the nonlinearity of the relationship between nutrient intake and income and on measurement error and endogeneity issues. One major finding is that income elasticity for calories is close to zero when we control for measurement error issues. For some nutrients, namely fats, vitamin A and C, calcium, and heme iron, we find a sizeable positive income elasticity robust to the choice of the estimator and percentiles at which it is evaluated. These nutrients are also those for which we find the largest deficiency in our sample. In addition, we find that for the poorest households in our sample, the deficiency of total energy, protein, and zinc is not accompanied by a positive income elasticity.
Tyrosine‐dependent basolateral targeting of human connexin43–eYFP in Madin–Darby canine kidney cells can be disrupted by the oculodentodigital dysplasia mutation L90V
Authors: Chtchetinin Jana , Gifford Wes D. , Li Sichen , Paznekas William A. , Jabs Ethylin Wang , Lai Albert
Published: October 2009

Polarized membrane sorting of connexin 43 (Cx43) has not been well‐characterized. Based on the presence of a putative sorting signal, YKLV(286–289), within its C‐terminal cytoplasmic domain, we hypothesized that Cx43 is selectively expressed on the basolateral surface of Madin–Darby canine kidney (MDCK) cells in a tyrosine‐dependent manner. We generated stable MDCK cell lines expressing human wild‐type and mutant Cx43–eYFP, and analyzed the membrane localization of Cx43–eYFP within polarized monolayers using confocal microscopy and selective surface biotinylation. We found that wild‐type Cx43–eYFP was selectively targeted to the basolateral membrane domain of MDCK cells. Substitution of alanine for Y286 disrupted basolateral targeting of Cx43–eYFP. Additionally, substitution of a sequence containing the transferrin receptor internalization signal, LSYTRF, for PGYKLV(284–289) also disrupted basolateral targeting. Taken together, these results indicate that Y286 in its native amino acid sequence is necessary for targeting Cx43–eYFP to the basolateral membrane domain of MDCK cells. To determine whether the F52dup or L90V oculodentodigital dysplasia ‐associated mutations could affect polarized sorting of Cx43–eYFP, we analyzed the expression of these Cx43–eYFP mutant constructs and found that the L90V mutation disrupted basolateral expression. These findings raise the possibility that some oculodentodigitial dysplasia‐associated mutations contribute to disease by altering polarized targeting of Cx43.
Unusual stability of human neuroglobin at low pH – molecular mechanisms and biological significance
Authors: Picotti Paola , Dewilde Sylvia , Fago Angela , Hundahl Christian , De Filippis Vincenzo , Moens Luc , Fontana Angelo
Published: October 2009

Neuroglobin (Ngb) is a recently discovered globin that is predominantly expressed in the brain, retina and other nerve tissues of human and other vertebrates. Ngb has been shown to act as a neuroprotective factor, promoting neuronal survival in conditions of hypoxic–ischemic insult, such as those occurring during stroke. In this work, the conformational and functional stability of Ngb at acidic pH was analyzed, and the results were compared to those obtained with Mb. It was shown by spectroscopic and biochemical (limited proteolysis) techniques that, at pH 2.0, apoNgb is a folded and rigid protein, retaining most of the structural features that the protein displays at neutral pH. Conversely, apoMb, under the same experimental conditions of acidic pH, is essentially a random coil polypeptide. Urea‐mediated denaturation studies revealed that the stability displayed by apoNgb at pH 2.0 is very similar to that of Mb at pH 7.0. Ngb also shows enhanced functional stability as compared with Mb, being capable of heme binding over a more acidic pH range than Mb. Furthermore, Ngb reversibly binds oxygen at acidic pH, with an affinity that increases as the pH is decreased. It is proposed that the acid‐stable fold of Ngb depends on the particular amino acid composition of the protein polypeptide chain. The functional stability at low pH displayed by Ngb was instead shown to be related to hexacoordination of the heme group. The biological implications of the unusual acid resistance of the folding and function of Ngb are discussed.
The changing patterns of covalent active site occupancy during catalysis on a modular polyketide synthase multienzyme revealed by ion‐trap mass spectrometry
Authors: Hong Hui , Leadlay Peter F , Staunton James
Published: October 2009

A catalytically competent, homodimeric diketide synthase comprising the first extension module of the erythromycin polyketide synthase was analysed using MS, after limited proteolysis to release functional domains, to determine the pattern of covalent attachment of substrates and intermediates to active sites during catalysis. Using the natural substrates, the acyltransferase and acylcarrier protein of the loading module were found to be heavily loaded with propionyl starter groups, while the ketosynthase was fully propionylated. The acylcarrier protein of the extension module was partly occupied by the product diketide, and the adjacent chain‐releasing thioesterase domain was vacant, implying that the rate‐ limiting step is transfer of the diketide from the acylcarrier protein to the thioesterase domain. The data suggest an attractive model for preventing iterative chain extension by efficient repriming of the ketosynthase domain after condensation. Use of the alternative starter unit valeryl‐CoA produced an altered pattern, in which a significant proportion of the extension acylcarrier protein was loaded with methylmalonate, not diketide, consistent with the condensation step having become an additional slow step. Strikingly, when NADPH was omitted, the extension acylcarrier protein contained methylmalonate and none of the expected keto diketide, in contrast to results obtained previously by mixing individual recombinant domains, showing the importance of also studying intact modules. The detailed patterns of loading of the extension acylcarrier protein (of which there are two in the homodimer) also provided the first evidence for simultaneous loading of both acylcarrier proteins and for the coordination of timing between the two active centres for chain extension.
Sub‐Chronic Exposure to Methylmercury at Low Levels Decreases Butyrylcholinesterase Activity in Rats
Authors: Valentini Juliana , Vicentini Juliana , Grotto Denise , Tonello Raquel , Garcia Solange C. , Barbosa Jr Fernando
Published: October 2009

Abstract: In this study, we examined the effects of low levels and sub‐chronic exposure to methylmercury (MeHg) on butyrylcholinesterase (BuChE) activity in rats. Moreover, we examined the relationship between BuChE activity and oxidative stress biomarkers [δ‐aminolevulinic acid dehydratase (δ‐ALA‐D) and malondialdehyde levels (MDA)] in the same animals. Rats were separated into three groups (eight animals per group): (Group I) received water by gavage; (Group II) received MeHg (30 μg/kg/day) by gavage; (Group III) received MeHg (100 μg/kg/day). The time of exposure was 90 days. BuChE and ALA‐D activities were measured in serum and blood, respectively; whereas MDA levels were measured in plasma. We found BuChE and ALA‐D activities decreased in groups II and III compared to the control group. Moreover, we found an interesting negative correlation between plasmatic BuChE activity and MDA (r = −0.85;p < 0.01) and a positive correlation between plasmatic BuChE activity and ALA‐D activities (r = 0.78;p < 0.01), thus suggesting a possible relationship between oxidative damage promoted by MeHg exposure and the decrease of BuChE activity. In conclusion, long‐term exposure to low doses of MeHg decreases plasmatic BuChE activity. Moreover, the decrease in the enzyme is strongly correlated with the oxidative stress promoted by the metal exposure. This preliminary finding highlights a possible mechanism for MeHg to reduce BuChE activity in plasma. Additionally, this enzyme could be an auxiliary biomarker on the evaluation of MeHg exposure.
Apoptin Enhances Radiation‐Induced Cell Death in Poorly Responding Head and Neck Squamous Cell Carcinoma Cells
Authors: Schoop Remilio A. L. , Verdegaal Elizabeth M. E. , De Jong Robert J. Baatenburg , Noteborn Mathieu H. M.
Published: October 2009

Abstract:  Treatment of head and neck cancers is still rather poor and worldwide new treatment options are sought. Sensitizing radioresistant tumours by combining irradiation with other therapeutics to induce apoptosis are widely investigated. We examined whether chicken anaemia virus‐derived apoptin protein would have a beneficial effect on irradiation of radiosensitive SCC61 and radioresistant SQD9 human head and neck squamous carcinoma cell lines. In both cell lines, concurrent exposure to irradiation and apoptin resulted in analysed mitochondrial cytochrome c release and in cleavage of caspase‐3, whereas irradiation alone of SQD9 cells under identical conditions did not. Moreover, in comparison with the irradiation, only the synchronized treatment of apoptin and irradiation resulted in increased cell death in especially the radioresistant SQD9 cells, as measured by means of a colony survival assay. Our data reveal that apoptin treatment represents an effective way for enhancing radiotherapy of tumours responding poorly to radiotherapy.
Molecular analysis of HumDN1 VNTR polymorphism of the human deoxyribonuclease I in systemic lupus erythematosus
Authors: AlFadhli Suad , AlTamimy Bader , Kharrat Najla , AlSaeid Khalid , Haider Mohamad Z. , Rebai Ahmed
Published: October 2009

Deoxyribonuclease I (DNASE1) may be responsible for the removal of DNA from nuclear antigens at sites of high cell turnover, thus preventing the onset of systemic lupus erythematosus (SLE). The purpose of this study was to screen DNASE1 gene for mutations that may have an effect on susceptibility to develop SLE. DNA was extracted from 76 Kuwaiti SLE patients and 92 race‐matched controls. PCR‐direct sequencing was used to screen DNASE1 promoter, coding sequence and exon–intron boundaries for mutation. Association of genomic variations was assessed using a Chi‐square test. Molecular analysis of the DNASE1 gene did not reveal any mutation. However, a 56‐bp repeat was detected in intron4 which was previously reported and named HumDN1. The allelic and genotypic distributions of the HumDN1 VNTR were compared between SLE patients and healthy subjects. Alleles were denoted as 2, 3, 4, 5 and 6 corresponding to the number of repeats of the 56 bp unit. Alleles 4, 5, and 6 showed significant association with SLE. Allele 5 showed the highest association [χ2 = 32.57; P ≤ 0.001; OR = 4.16; 95% CI: (2.55–6.79)]. Association of allele 5 was also found at the genotypic level, where genotype 5/5 is more prevalent in SLE subjects as compared with controls (17% versus 9%). We report a significant association of HumDN1 VNTR polymorphism in DNASE1 gene with SLE. Further functional assays needed to assess the effect of this VNTR on DNASE1 activity and its association with SLE.
Acreage Response to Weather, Yield, and Price
Authors: Weersink Alfons , Cabas Juan H. , Olale Edward
Published: October 2009

This paper examines the effect of weather on the distribution of yield and its subsequent impact on the acreage allocation decisions of crop farmers in Ontario. The mean and variance of yield are estimated for corn, soybeans, and winter wheat for eight counties in Ontario over a 26‐year period. The predicted parameters of the yield distribution are then used along with expectations on the distribution of crop price to estimate area response functions. A principal contribution of the paper is the decomposition of the revenue impact on crop area allocation into separate average and variance contributions for both price and yield. This decomposition illustrates the importance of expected yield in the area allocation decisions. Crop yield is especially influenced by the length of the growing season and this has a significant impact on acreage allocations. This implies that crop area will be altered in response to expected changes in climate, even without shifts in crop prices.

Le présent article examine l'incidence des facteurs météorologiques sur la distribution des rendements et leurs conséquences sur les décisions des producteurs agricoles de l'Ontario concernant l'allocation des superficies cultivées. Nous avons estimé la moyenne et la variance des rendements pour le maïs, le soja et le blé d'automne cultivés dans huit comtés ontariens au cours d'une période de 26 ans. Les paramètres prédits de la distribution des rendements et l'espérance de la distribution du prix des cultures ont été utilisés pour estimer les fonctions de réponse par région. La décomposition de l'impact du revenu sur l'allocation des superficies cultivées en terme d'effets sur les moyennes et les variances des prix et des rendements constitue une importante contribution de l'article. Cette décomposition montre l'importance des rendements prévus dans les décisions d'allocation des superficies. Le rendement de culture est particulièrement influencé par la longueur de la saison de croissance qui a une incidence considérable sur l'allocation des superficies cultivées. Par conséquent, les superficies cultivées seront influencées par les changements climatiques prévus, et ce, même en l'absence de fluctuation du prix des cultures.
Neuropathology of Olfactory Ensheathing Cell Transplantation into the Brain of Two Amyotrophic Lateral Sclerosis (ALS) Patients
Authors: Giordana Maria Teresa , Grifoni Silvia , Votta Barbara , Magistrello Michela , Vercellino Marco , Pellerino Alessia , Navone Roberto , Valentini Consuelo , Calvo Andrea , Chiò Adriano
Published: October 2009

Although a large number of amyotrophic lateral sclerosis (ALS) patients have undergone transplantation procedures with olfactory ensheathing cells (OECs) in the Bejing Hospital, to our knowledge, no post‐mortem neuropathologic analyses have been performed. We examined the post‐mortem brain of two Italian patients affected by ALS who underwent cellular transplantation in Beijing with their consent. Our aim was to assess the events following the graft procedure to possibly support the rationale of the treatment strategy. The neuropathologic findings were analyzed on the basis of the limited awareness of the experimental conditions and discussed in relation to the safety, efficacy and long‐term outcome of the transplanted cells. Islands of quiescent, undifferentiated cells within the delivery track persisting for up to 12 months–24 months were found. Prominent glial and inflammatory reaction around the delivery track strongly supports the encasement of the graft. Evidence of axonal regeneration, neuronal differentiation and myelination was not seen. The surgical procedure of implantation was not compatible with a neurotrophic effect. The OEC transplantation did not modify the neuropathology of ALS in the two patients. In conclusion, the present neuropathologic analysis does not support a beneficial effect of fetal OEC implantation into the frontal lobes of ALS patients.
The Effectiveness of couple therapy in Germany: A Replication Study
Authors: Klann Notker , Hahlweg Kurt , Baucom Donald H. , Kroeger Christine
Published: October 2009

The utility of couple therapy has been investigated in a number of controlled clinical efficacy investigations, demonstrating the superiority of most forms of couple therapy relative to control groups. Despite its widespread use, the effectiveness of couple therapy in field settings is largely unknown. In 1997, Hahlweg and Klann published an effectiveness study of couple therapy as practiced in German and Austrian marital counseling agencies. The purpose of the current investigation was to replicate their earlier findings in a similar setting with identical measures. The findings demonstrate that the results are remarkably similar across the two studies and that couple therapy in these applied settings helps to alleviate relationship distress as well as individuals’ depression.
Understanding the Experience of Black Clients in Marriage and Family Therapy
Authors: Awosan Christiana I. , Sandberg Jonathan G. , Hall Cadmona A.
Published: October 2009

Past research on Black clients’ utilization of therapy focused on the barriers that prevent Black clients from attending therapy and the reasons for these barriers. However, few studies have been conducted that focus on how Black clients attending therapy actually experience these barriers. This study utilized both Likert and open‐ended questions to examine the obstacles 16 Black clients face in their attempts to attend family therapy. The most frequently identified obstacles were related to concerns over family member response and cultural barriers to therapy. Participants also reported concerns about racial and/or cultural differences and a lack of understanding by non‐Black therapists. The implications of this study addressed how to effectively meet the therapeutic needs of Black clients.
Relationship Among Differentiation of Self, Relationship Satisfaction, Partner Support, and Depression in Patients With Chronic Lung Disease and Their Partners
Authors: Lal Arpita , Bartle‐Haring Suzanne
Published: October 2009

The purpose of the present study is to test the relationships among differentiation of self, relationship satisfaction, perceived partner support, and depression in a sample of patients with chronic lung disease (CLD) and their partners. The sample consisted of 52 patients with CLD and their partners. Hierarchical multiple regression was used for data analysis. The results indicate that (a) patients’ differentiation of self is significantly lower than partners’ differentiation of self, (b) patients’ relationship satisfaction is positively correlated with partners’ relationship satisfaction, (c) patients’ relationship satisfaction predicts perceived partner supportive behavior, (d) perceived partner unsupportive behavior predicts patients’ depression, (e) partners’ differentiation of self predicts partners’ relationship satisfaction, (f) partners’ relationship satisfaction predicts partner supportive behavior, and (g) partners’ differentiation of self and relationship satisfaction predicts partners’ depression. The study serves to highlight the fact that the patient is part of a system, and that taking the system into account is relevant to the well‐being of both the patient and the partner, in particular for patients with CLD, a heretofore unstudied population. The results of such studies have significant implications for couple and family therapists.
Identification of stomatopod larvae (Crustacea: Stomatopoda) from Hong Kong waters using DNA barcodes
Authors: TANG RICKY W. K. , YAU CYNTHIA , NG WAI‐CHUEN
Published: October 2009

The Stomatopoda (Crustacea: Malacostraca) from the South China Sea region are of commercial importance and although limited studies have been conducted on the adults, no research has ever been attempted on the larval stages because of the lack of identification keys or taxonomic descriptions. In the first study of its kind in the region, DNA barcoding was used successfully to identify unknown stomatopod larvae from plankton samples. Sequences of two mitochondrial genes, namely the cytochrome c oxidase subunit‐I (COI) and the large ribosomal subunit (16S) rRNA, were applied as the barcodes to match DNA sequences from unknown larval morphotypes against those of known, locally occurring adult species. Intraspecific variations for the COI and 16S rRNA genes were found to be <2.4% and <2.1% respectively in terms of Kimura 2‐Parameter (K2P) divergence of the adults, whereas variations between genera ranged from 13% to 24% and 3% to 11% respectively. These results imply that both genes are suitable for use in species identification of stomatopods; thus 14 of the 16 larval morphotypes (87.5%) obtained in Hong Kong waters can be identified to seven species through DNA barcoding. The findings of this study would also facilitate future research on the larval ecology and phylogenetic relationship of these crustaceans.
Piston Vibration in Piston-Cylinder Systems
Authors: Etsion I. , Magen M.
Published: October 2009

The motion of a cylindrical piston falling in a liquid filled vertical cylinder is analyzed. It is found that concentric motion is impossible and that flow induced vibration is always associated with such piston-cylinder systems. If the clearance over radius ratio is larger than a certain critical value, βcr, severe wobble and piston-cylinder contact occurs. For clearance over radius ratio less than βcr stable periodical oscillation with a constant amplitude takes place and the piston never contacts the cylinder wall. Reasonable agreement is achieved between the theoretical results and previous experimental observation.
Velocity Characteristics of Confined Coaxial Jets With and Without Swirl
Authors: Habib M. A. , Whitelaw J. H.
Published: October 2009

Measured values of the velocity characteristics of turbulent, confined, coaxial-jet flows have been obtained, without swirl, for ratios of maximum annulus to pipe velocities of 1.0 and 3.0 and with a swirl number of 0.23 for a velocity ratio of 3.0. They were obtained by a combination of pressure probes, hot-wire and laser-Doppler anemometry. The results are compared with calculations, based on the solution of finite-difference forms of the steady, Navier-Stokes equations, and an effective-viscosity hypothesis. The measurements allow the influence of confinement and swirl to be quantified and show, for example, the increased tendency towards centerline recirculation which results from both. The results with the three types of instrumentation allow a comparison within the corner recirculation region which reveals that serious errors of interpretation of mean-velocity measurements need not arise. The two-equation model, although able to represent the non-swirling flow is less appropriate to the swirling flow and the reasons are indicated.
Hydraulic Axial Thrust in Multistage Centrifugal Pumps
Authors: Iino T. , Sato H. , Miyashiro H.
Published: October 2009

An experimental and theoretical study is performed with a single stage pump. The influence of the flow rate, the axial displacement of the impeller, and annular seal clearances on the hydraulic axial thrust is investigated. Pressure distributions measured in the space between the impeller and the casing agree with those calculated by the Kurokawa-Toyokura method when the leakage flow is inward in the space. It is clarified that the method is sometimes not available for the outward leakage flow because of the large thickness of the boundary layer in the space. A computer program for calculating the axial thrust in multistage centrifugal pumps is developed based on the method and experimental results. Axial thrusts measured in prototype multistage pumps agree with the calculation.
A Quasi-Standing-Wave Phenomenon Due to Oscillating Internal Flow
Authors: Rockwell D. , Schachenmann A.
Published: October 2009

The objective of this investigation is to characterize a quasi-standing-wave pattern having a wavelength two orders of magnitude smaller than the corresponding acoustic wavelength, and relate it to the presence of: a) a downstream travelling wave due to vortical structures generated in a free shear layer, and b) downstream and upstream propagating acoustic waves. In this experiment, the vortical structures were generated by flow past an axisymmetric cavity and their influence extended downstream through the exhaust pipe. The amplitudes of the acoustic waves were associated with Helmholtz resonance of the upstream settling chamber. A linear theory models well the measured amplitude and phase distributions of the fluctuating velocity in the core flow. As system resonance is approached, the ratio of vortex wave amplitude to acoustic wave amplitude decreases. The consequence is an increase in the magnitude and gradient of the phase change across the node, or amplitude minimum, of the resultant standing-wave pattern. In addition, the peak-to-peak amplitude of the quasi-standing-wave increases. A variety of internal (and external) flow systems, including unsteady phenomena in wind tunnels, may be subject to this flow mechanism when the frequency of coherent vortex formation in the test section lies near the Helmholtz resonance frequency of the upstream settling (or plenum) chamber.
Flow in the Initial Region of Axisymmetric Turbulent Jets
Authors: Islam S. M. N. , Tucker H. J.
Published: October 2009

In the initial region of axisymmetric turbulent jets a core of uniform velocity is assumed to exist, bounded by an annular free shear layer. An empirical model for axial mean velocity is found from experimental measurements using a length scale which forces self-preservation in the central part of the free shear layer. This model is applied to the integral form of the momentum and energy equations, subject to the boundary layer simplifications, to obtain an approximate solution for the development of jets where the thickness of the mixing layer at the nozzle exit is assumed negligible. The differential form of momentum and continuity equations are also solved by a finite difference technique of DuFort-Frankel type using a typical boundary layer type of velocity profile at the exit of the nozzle. The results of this method are compared with those of the empirical velocity method, and the present and existing experimental results. Prandtl’s mixing length is shown to be a slightly nonlinear function of the axial distance and is used to define the eddy diffusivity for this region.
Turbulent Flow in Axially Rotating Pipes
Authors: Murakami Mitsukiyo , Kikuyama Kouji
Published: October 2009

Experimental results concerning the flow pattern and hydraulic resistance in a rotating pipe are described. A fully developed turbulent flow was introduced into a long smooth pipe rotating about its axis, and changes of the flow pattern, together with hydraulic loss within the pipe, were examined by measuring the velocity and pressure distributions across sections at various distance from the pipe entrance. Increase of pipe rotation continuously reduces the hydraulic loss and gradually changes the axial velocity profile from a turbulent type to a laminar one. Governing factors for these changes are discussed.
Review—Axial Compressor Stall Phenomena
Authors: Greitzer E. M.
Published: October 2009

Stall in compressors can be associated with the initiation of several types of fluid dynamic instabilities. These instabilities and the different phenomena, surge and rotating stall, which result from them, are discussed in this paper. Assessment is made of the various methods of predicting the onset of compressor and/or compression system instability, such as empirical correlations, linearized stability analyses, and numerical unsteady flow calculation procedures. Factors which affect the compressor stall point, in particular inlet flow distortion, are reviewed, and the techniques which are used to predict the loss in stall margin due to these factors are described. The influence of rotor casing treatment (grooves) on increasing compressor flow range is examined. Compressor and compression system behavior subsequent to the onset of stall is surveyed, with particular reference to the problem of engine recovery from a stalled condition. The distinction between surge and rotating stall is emphasized because of the very different consequences on recoverability. The structure of the compressor flow field during rotating stall is examined, and the prediction of compressor performance in rotating stall, including stall/unstall hysteresis, is described.
Combined Simultaneous Flow Visualization/Hot-Wire Anemometry for the Study of Turbulent Flows
Authors: Falco R. E.
Published: October 2009

The measurement of coherent motions in turbulent and unsteady flows is discussed. A technique which discriminates these motions based upon the patterns they create by scattering light from a fog of tiny oil drops is described. It is shown that hot-wire anemometry can be used in this oil fog so that hot-wire data can be conditionally sampled to the visual patterns, giving directly interpretable measures of the importance of the selected features. The three-dimensionality of the coherent motions can also be directly accounted for, using mutually orthogonal sheets of light. Results of step flows, and zero and favorable pressure gradient flows are described.
Lower Mode Response of Circular Cylinders in Cross-Flow
Authors: Durgin W. W. , March P. A. , Lefebvre P. J.
Published: October 2009

Transverse amplitude responses of a circular cylinder in cross-flow were determined as a function of reduced velocities for a variety of spring constants and damping coefficients. Maxima were found at reduced velocities of 5 and 16, and were of comparable amplitude. The first resonance, designated the “fundamental mode,” was due to normal vortex street excitation of the spring-mass system. The second resonance, designated the “lower mode,” occurred when the natural frequency was approximately one-third of the normal vortex shedding frequency. By assuming that the driving force was sinusoidal, it was possible to evaluate the lift coefficients at resonance. Lift coefficients for the lower mode behaved similarly with amplitude ratio but were an order of magnitude lower than lift coefficients for the fundamental mode. A mechanism was used to oscillate the cylinder transversely at prescribed frequencies and amplitudes. Dominant wake frequencies were determined from a frequency analysis of the hot-wire signal for a range of velocities and a fixed frequency of oscillation. It was found that synchronization of the shedding frequency to the forcing frequency did not take place for the lower mode. The familiar “lock-in” region, or frequency synchronization over finite bandwidth, was observed for the fundamental mode only. Since the frequency associated with normal vortex shedding was not suppressed when oscillations took place in the lower mode, it would seem that a low frequency vortex street had not replaced the normal one. It is likely, then, that the spring-mounted cylinder responded subharmonically to the exciting force resulting from vortex shedding. In this regard, however, it was curious that subharmonic response was not found at a frequency ratio of 0.5 as it was at 0.33. A conceptual model, which incorporated features of both the low frequency vortex street and subharmonic response, was developed which accounted for lower mode response at a frequency ratio of 0.33 as well as the lack of response at 0.5.
Measurement of Instantaneous Pressure and Velocity in Nonsteady Three-Dimensional Water Flow by Means of a Combined Five-Hole Probe
Authors: Matsunaga S. , Ishibashi H. , Nishi M.
Published: October 2009

A new combined five-hole probe with hemispherical head of 2.0 mm diameter is developed for the measurement of nonsteady three-dimensional water flow. Each pressure hole is connected to a small semiconductor pressure transducer, which has a high frequency response, and the instantaneous pressure can be measured continuously by the probe. In the case of nonsteady flow, pressures detected by the probe are affected by the inertia due to flow unsteadiness. Therefore, in order to achieve an accurate nonsteady flow measurement, it is vital to reduce the inertial effects from the pressure reading. In the present study the inviscid flow analysis was carried out to evaluate the error due to the inertial effect, and the iterative correction procedure was examined by computer simulation.
Viscous Liquid Films in Nonradial Rotating Pipes[1]
Authors: Dakin J. T.
Published: October 2009

The dynamics of a thin liquid film flowing through a rotating pipe are studied. The flow is assumed to be fully developed and dominated by viscous forces. The fluid is drawn along the pipe by the centrifugal force. The pipe is tilted with respect to the radial direction so that the centrifugal force has a component perpendicular to the pipe axis. An approximate dynamic model is developed which describes the film surface shape, and which includes the effects of the Coriolis-induced secondary motion. Several simple, interesting solutions are presented.
The Effect of Blade-Wakes on the Performance of Short Dump-Diffuser Type Combustor Inlets
Authors: Klein A. , Pucher P. , Rohiffs M.
Published: October 2009

Experimental results are presented of the effects of flow distortions, generated by a compressor cascade, on the performance of a short annular dump-diffuser type combustor inlet. The distance between the cascade and the diffuser entrance plane was varied. The losses increase substantially when this distance becomes small. In most of the tests the losses turned out to be minimum at a distance of about two blade-chord lengths. When the cascade was removed, the losses were higher than this minimum value. Evidence is presented that the radial blockage factor rather than the total blockage factor determines the magnitude of the losses.
Flow Measurements in a Turbine Scroll
Authors: Tabakoff W. , Sheoran Y. , Kroll K.
Published: October 2009

A study was conducted to determine experimentally the flow behavior in the combined scroll nozzle assembly of a radial inflow turbine. Hot film anemometry technique was used to measure the flow velocity in the scroll.
The Flow Properties of Rooms With Small Ventilation Openings
Authors: Gosman A. D. , Nielsen P. V. , Restivo A. , Whitelaw J. H.
Published: October 2009

Measured and calculated properties relevant to the flow in ventilated rooms are reported. The measurements were obtained by laser-Doppler anemometry in a small-scale model room with a single square inlet. The calculations made use of a numerical procedure which solves, in finite-difference form, the elliptic partial-differential equations for three components of velocity, the pressure, the turbulence energy and its dissipation rate. Calculated results are shown to be in close agreement with the present measurements and with other available experimental data. With this justification, the procedure is used to quantify the dependence of the velocity characteristics of different geometric arrangements. The results provide guide lines for the design of ventilation systems.
Calculation of Turbulent Wall Jets With an Algebraic Reynolds Stress Model
Authors: Ljuboja M. , Rodi W.
Published: October 2009

A modified version of the k-ε turbulence model is developed which predicts well the main features of turbulent wall jets. The model relates the turbulent shear stress to the mean velocity gradient, the turbulent kinetic energy k, and the dissipation rate ε by way of the Kolmogorov-Prandtl eddy viscosity relation and determines k and ε from transport equations. The empirical constant in the Kolmogorov-Prandtl relation is replaced by a function which is derived by reducing a model form of the Reynolds stress transport equations to algebraic expressions, retaining the wall damping correction to the pressure-strain model used in these equations. The modified k-ε model is applied to a wall jet in stagnant surroundings as well as to a wall jet in a moving stream, and the predictions are compared with experimental data. The agreement is good with respect to most features of these flows.
Turbulent Boundary Layers With Unsteady Injection-Suction
Authors: Tsahalis D. T.
Published: October 2009

The time dependent turbulent boundary-layer equations with a two-layer eddy viscosity model are integrated numerically over a porous flat plate for a steady outer flow and a sinusoidally distributed injection-suction that varies harmonically with time. The dependence of the unsteady wall shear on the frequency and strength of injection-suction is investigated. The present results indicate that the time-averaged skin friction is always larger than the skin friction observed over a nonporous flat plate. Comparison with previous theoretical results indicates that the time-averaged skin friction is always smaller than the skin friction observed over a porous flat plate with steady, simultaneous injection-suction of the same strength. The extension of eddy viscosity models, developed for steady flows, to unsteady flows is discussed.
A Laser-Two-Focus (L2F) Velocimeter for Automatic Flow Vector Measurements in the Rotating Components of Turbomachines
Authors: Schodl R.
Published: October 2009

Numerous results—most of them are published—have proved the applicability of the L2F-velocimeter to experimental studies of the complex compressor flow: e.g. the blade wakes and the shock-wave system within the blade passages. Furthermore, measurements close to the compressor surfaces provide information about boundary layers and flow separation. However, the measuring procedure is rather time-consuming. It takes about one hour to accumulate 10 to 15 vector measurements within a rotor blade channel. This paper presents a technique whereby the measuring time is reduced by a factor of ten. Mathematical considerations of the L2F-signal statistics lead to a modified calculation model and a new measuring procedure. Now, about 100 to 150 flow points can be acquired in one hour which includes the magnitude and direction of the mean flow vector as well as its turbulent components. This paper describes the innovations in optics, operational procedures, and electronics that have resulted in an enhanced state-of-the-art in flow measurement. Experimental results are also submitted and discussed.
Velocity and Pressure Distributions in the Impeller Passages of Centrifugal Pumps
Authors: Murakami M. , Kikuyama K. , Asakura E.
Published: October 2009

The flow patterns in centrifugal pump impellers with three and seven blades, respectively, were measured using a cylindrical yaw probe and an oil surface flow method. The measured distributions of velocities and pressures for the seven (sufficient number) blade impeller at the design flow rate coincide well with the numerical solution obtained from the theoretical equation based on a potential flow. The flow patterns of the three (insufficient number) blade impeller deviate largely from those of the seven blade impeller both at the design and off-design conditions. The values of the slip factor deduced from the data of velocity measurements in the impeller passage were compared with those calculated by commonly-used formulae, and considerably good agreement was obtained for the seven blade impeller.
System to Measure the Pressure Distribution on Fan Aerofoil Surfaces During Flutter Conditions
Authors: Chivers John W. H.
Published: October 2009

In order to assist in the understanding of high speed flutter, a series of tests has been conducted on a research fan in which the blade surface pressures have been measured by means of miniature silicon diaphragm pressure transducers embedded in selected fan blades. Prior to this investigation a program of rig tests was conducted to examine the effects of centrifugal force and vibration on the transducer performance and a transducer mounting technique was developed to minimize blade induced stress in the transducer. Instantaneous measurements of the tip stagger angles of the pressure instrumented fan blades have enabled a cross correlation to be performed on the blade surface pressure data and the blade tip angles. Some typical test results are shown.
Flow Prediction in Rotating Ducts Using Coriolis-Modified Turbulence Models
Authors: Howard J. H. G. , Patankar S. V. , Bordynuik R. M.
Published: October 2009

A parabolic numerical analysis procedure has been used to predict the flow in a straight, radial rotating channel of rectangular cross-section, chosen as a simple model of an impeller passage. A two equation turbulence model was employed, with alternative modifications, to include the influence of Coriolis force on turbulent kinetic energy. Alternative Coriolis force terms were evaluated by comparisons in a high-aspect-ratio duct with measured velocity, wall shear stress and turbulent viscosity. Secondary velocity predictions were checked with data from a low-aspect-ratio duct where the Coriolis modification of turbulence was found less influential than the secondary flow in the modification of side wall shear stress.
Evaluation of Vehicle Drag Parameters From Coastdown Experiments Conducted Under Nonideal Environmental Conditions
Authors: Korst H. H. , White R. A.
Published: October 2009

Parameter identification by optimization forms the analytical basis for extracting road load information from well controlled coastdown tests. Specific attention is given to the effects of both biased and random errors as may be caused by environmental disturbances, road conditions, inaccurate parameteric input, or signal and instrument noise. As a consequence, experimental conditions can be identified and quantitative criteria established for either avoiding or correcting such errors. Test results are presented which support the methodology and conclusions.
A Photographic Study of Cavitation in Jet Flow
Authors: Hoyt J. W. , Taylor J. J.
Published: October 2009

The effect of polymer additives on underwater jet cavitation has been studied using a special camera. Solutions of the drag-reducing additives, polyacrylamide and poly(ethylene oxide), at concentrations of 25 ppm, decreased the cavitation inception index and greatly changed the appearance of the cavitation bubbles. Solutions of the non drag-reducing polymer, Carbopol, produced cavitation bubbles having the same appearance on pure water and did not change the inception index. In pure water, the cavitation appearance resembles ragged groups of small bubbles with the overall impression of sharpness and roughness, but in drag-reducing polymer solutions the bubbles are larger, rounded, and of completely different appearance.
The Effect of Cross-Winds on Trains
Authors: Cooper R. K.
Published: October 2009

Low mass, high speed trains may be in danger of being overturned by strong crosswinds. This paper examines the aerodynamic data required to estimate overturning wind speeds. The results of wind tunnel tests and a moving model experiment, including the effect of the turbulent wind, are described.