bluuebunny/crossref_metadata_2025 huggingface dataset:
HEAT‐INDUCED PROTEIN AGGREGATES AND DIFFERENCE IN THE TEXTURAL PROPERTIES OF WHOLE MILK GEL
Authors: WANG WEIJUN , ZHANG LANWEI , LI YANHUA , FENG ZHEN
Published: May 2012

The effects of heat on milk protein aggregates and the changes in the textural properties of whole milk gels induced by acid or rennet were investigated. Milk samples were heated at 70, 80 and 90C for 15, 30, 45 and 60 s. Acid gels prepared from heating whole milk showed larger values for hardness, adhesiveness and viscosity than the gels from unheated milk, while the corresponding rennet gels showed lower values when compared with the gels from unheated milk. These results reflect the changes in the heat‐induced protein aggregates, which were examined by size exclusion chromatography using Sephacryl S‐500 High Resolution (GE, Piscataway, NJ). It was also demonstrated that the protein aggregates were an important factor for milk gelation by active influence on acid gels and negative influence on rennet gels.

PRACTICAL APPLICATIONS

Heat‐induced whey protein‐rich cheeses are gaining in popularity for various reasons such as reducing the risk of pathogens and improving the cheese yield. However, the heat treatment can lead to changes in texture. As a part of the whole study on whey protein‐rich cheese, the research analyzed the effects of high pasteurization on textural properties of the whole milk gels induced by rennet or acid. The results observed should guide the study on modification of protein aggregates, such as the use of an acidifier, and enable manufacturer to make rennet gel with textural properties close to raw milk.
CHEMICAL AND MICROBIOLOGICAL CHARACTERISTICS OF SHALGAM (ŞALGAM): A TRADITIONAL TURKISH LACTIC ACID FERMENTED BEVERAGE
Authors: TANGULER HASAN , ERTEN HUSEYIN
Published: May 2012

Chemical and microbiological profiles of some commercial shalgams were investigated. The counts of lactic acid bacteria (LAB), mesophilic aerobic bacteria, yeasts, non‐Saccharomyces yeasts and coliform bacteria were found with average of 6.97, 6.72, 5.64, 4.47 and 1.49 log cfu/mL, respectively. The final amounts of total acidity as lactic acid were found in the range of 6.54–7.25 g/L and final pH levels in the range of 3.28–3.48. Lactic acid, acetic acid and ethanol were produced with the fermentation of sugars and their levels were ranged from 2.66 to 4.74 mg/L, from 0.345 to 1.19 mg/L and from 0.79 to 5.03 g/L, respectively. Research on shalgam microbiota is scarce. Lactobacillus (Lb.) plantarum, the predominant LAB, Lb. brevis, Lb. delbrueckii subsp. delbrueckii and Lb. fermentum were found in shalgam samples. We also found new species have not been isolated so far.

PRACTICAL APPLICATIONS

Shalgam (Şalgam) production and consumption are recently increasing in Turkey. It is also made in commercial scale. The results obtained from this study give some information on the proximate chemical composition of commercial shalgam samples. Microbiological data can help in selecting the most promising LAB for starter usage in shalgam production.
SENSORY LEXICON FOR MANGO AS AFFECTED BY CULTIVARS AND STAGES OF RIPENESS
Authors: SUWONSICHON S. , CHAMBERS IV E. , KONGPENSOOK V. , OUPADISSAKOON C.
Published: May 2012

A lexicon consisting of 20 flavor attributes and 11 texture attributes was developed by a highly trained descriptive panel to describe sensory characteristics of nine cultivars of ripe and green mangoes grown in Thailand. Results showed that the attributes were able to describe great variation both in flavor and texture characteristics among samples. Principal component analysis grouped the attributes into six key dimensions that explained 73.3% of total variability of all mango samples. However, all the attributes were needed to explain the complete variation among samples. Attributes such as mango identity, woody, various fruit notes, floral/perfumy, earthy, sweet, mealy, fiber amount and size, slickness, chemical, peel‐like, sour, bitter, piney and spicy differentiated among cultivars. Other attributes such as viney, green, firmness, cohesiveness of mass, astringent, particle amount and size, slimy, fermented, animalic, pulpy residue and starchy explained changes in sensory characteristics occurring during ripening of the fruit.

PRACTICAL APPLICATION

Mango is growing in popularity around the world. Mango cultivars vary greatly in aroma, flavor and texture, especially among the main types, ripe and green mango. This research provided information on how sensory characteristics, especially flavor and texture, differed among mango cultivars and how those characteristics changed during ripening of the fruit. This information could be useful for mango producers in selecting highly desirable traits while slowly eliminating less desirable traits of certain cultivar, and useful for mango exporters in selecting cultivars that will be successful in their target markets. The lexicon could also be used for future sensory research on mangoes.
Pharmacophore‐Based Virtual Screening to Aid in the Identification of Unknown Protein Function
Authors: Mallipeddi Prema L. , Joshi Manali , Briggs James M.
Published: May 2012

A pharmacophore‐based virtual screening method was developed and validated for use in predicting the function of a novel protein in terms of small metabolite binding. Five test cases were used for the validation study which spanned two different folds, four superfamilies, and three enzyme classes. Binding sites were predicted using a combination of two methods (CASTp and THEMATICS). The binding site was mapped with chemical probes representing hydrogen‐bond donor, acceptor, negative ionizable, positive ionizable, and hydrophobe. The interaction maps were converted to three or four feature pharmacophore models and used to search a database containing 80 018 tautomers/protomers/conformers of 10 535 metabolites. The pharmacophore‐based virtual screening eliminated >92% of the database as potential substrates and retrieved specific hits, which were ranked using a physics‐based scoring function. The known substrate or product was ranked within the top 0.7% and substrate‐like compounds within the top 1% of the metabolite database for all of the five test cases. The results suggest that using this pharmacophore‐based virtual screening is a time‐efficient strategy that can be applied to screen large databases to help predict the function of small metabolite binding proteins.
Human Creation in the Hebrew Bible and the Qur’an – Feminist Exegesis
Authors: Roded Ruth
Published: May 2012

The foundations of Judaism and Islam are their holy books – the Hebrew Bible and the Qur’an – which believers regard as the eternal word of God. It is not surprising, therefore, that leading Islamic and Jewish religious feminists undertook to reinterpret problematic and even misogynist verses and narratives. One of the earliest narratives addressed by both Jewish and Islamic religious feminists in interpreting the Hebrew Bible and the Qur’an was the creation of man and woman. In both religious traditions, the creation of the first woman after the man, from the man, and for the man served as a foundation stone of patriarchy. The challenge that Jews and Muslims faced in this endeavor differed as a function of the dissimilarity of the texts of the Hebrew bible and the Qur’an. The task of feminist exegesis was similarly motivated, however, by the long‐established interpretation of the texts by both Jewish and Muslim male scholars functioning in patriarchal societies, (and even the few women exegetes in the mid‐twentieth century). There is a remarkable resemblance in the methodology and approach of Jewish and Islamic religious feminists to their sacred books, but there does not appear to have been any direct influence of one on the other. The point of convergence seems to be through the Christian Eve and efforts by western Christian feminists to defuse this Biblical tradition. The similarity and parallels between Jewish and Islamic feminist exegesis may be attributed to the similar backgrounds of the women as well as the similar sociologies of Judaism and Islam and language issues.
The Problem of the Referring Person*
Authors: Palazzoli Mara Selvini , Boscolo Luigi , Cecchin Gianfranco , Prata Giuliana
Published: May 2012

This paper is a preliminary contribution to the potentially insidious problem of the referring person in family therapy. In our experience, our failure to examine this problem according to the systemic epistemology was the root of several unsuccessful therapies. A description of those who, most often, are the referring persons to be suspected of having become homeostatic members of the family is given. We also present sketches of the behavior we most often observe in families which are maintaining a homeostatic bond with the referring person. Lastly, we explain and give examples of the tactics devised by our team to reveal and resolve this problem.1
The Clinical Effects of Massive Psychic Trauma in Families of Holocaust Survivors*
Authors: Davidson Shamai
Published: May 2012

For years we have been treating numerous concentration camp survivors in the psychiatric clinics and hospitals of Israel. In recent years we have been seeing increasing numbers of the second generation suffering from a wide spectrum of emotional disorders, personality disturbances, borderline and psychotic states which are clearly related to the long‐term effects of massive traumatization in the survivor parents. These effects are manifest in four inter‐related areas of disturbance within the family—the parents' mental state, the family atmosphere, inter‐personal functioning in the family and specific distortions in the parent‐child interaction. Excessive talking about holocaust experiences to children, or the opposite —lack of communication, avoidance and denial of these experiences—are patterns frequently found in the children of survivors who seem to be most affected by the massive traumatization of the parents. It is postulated that therapy of the survivor parents can modify the transmissions of affects to the children. Family therapy is indicated whenever possible.
The Couple as a Unit: Sexual, Social and Behavioral Considerations To Reproductive Barriers*
Authors: Mudd Emily H.
Published: May 2012

Sexual, social, and behavioral considerations which may contribute as reproductive barriers are discussed. Much effort has gone into study and experience in aiding the infertile couple. Yet there is no demonstrated empirical agreement on what constitute psychogenic factors involved or their etiology.

Cases of two young infertile couples counseled are presented. Medical and relationship difficulties are explored. In one situation a decision is arrived at to attempt parenthood through artifical insemination. In the other, pregnancy occurred by natural means. Family backgrounds, marital relationships, personality attributes, and long‐distance goals highlight complexities needing consideration. Decisions were not rushed. Time can be a helpful ally.
Alcoholics Anonymous and Family Therapy*
Authors: Davis Donald I.
Published: May 2012

Alcoholism affects the family of the alcoholic as well as the individual problem drinker. Change in drinking behavior is often brought about by change in the alcoholic's family members. There has been a natural evolution in the alcoholism field of self‐help groups for mates and children of alcoholics. This development has paralleled the recent growth and development of family therapy as a major mode of psychotherapeutic intervention. Yet, crossfertilization of ideas and intervention strategies between the two fields has been slow in occurring. Arguments over whether one uses family therapy or A.A. and Al‐Anon persist. This paper focuses on ways in which family therapy and the A.A. self‐help groups add to, rather than detract from, one another. A note of caution about the misuse of family therapy when alcoholism is present is also provided.1
Correlates of Engagement in Family Therapy
Authors: Le Fave M. Keith
Published: May 2012

Sixty‐five families who continued in conjoint family therapy were compared on a variety of antecedent variables to 65 families who dropped out. The following factors were found to be associated with engagement in therapy: (a) age of the identified patient; (b) number of children in the family; (c) the family's prior involvement with community agencies; (d) the presence or absence of antisocial acting‐out; and (e) attendance of father at both the initial intake interview and early treatment sessions. Maximal discrimination between continuing and dropout families was demonstrated by simultaneous consideration of several significant variables. The implication of these results for family therapy selection criteria are discussed.
Characterizing the physical and genetic structure of the lodgepole pine × jack pine hybrid zone: mosaic structure and differential introgression
Authors: Cullingham Catherine I. , James Patrick M. A. , Cooke Janice E. K. , Coltman David W.
Published: May 2012

Understanding the physical and genetic structure of hybrid zones can illuminate factors affecting their formation and stability. In north‐centralAlberta, lodgepole pine (Pinus contortaDougl. exLoud. var.latifolia) and jack pine (Pinus banksianaLamb) form a complex and poorly defined hybrid zone. Better knowledge of this zone is relevant, given the recent host expansion of mountain pine beetle into jack pine. We characterized the zone by genotyping 1998 lodgepole, jack pine, and hybrids fromBritishColumbia,Alberta,Saskatchewan,Ontario, andMinnesota at 11 microsatellites. UsingBayesian algorithms, we calculated genetic ancestry and used this to model the relationship between species occurrence and environment. In addition, we analyzed the ancestry of hybrids to calculate the genetic contribution of lodgepole and jack pine. Finally, we measured the amount of gene flow between the pure species. We found the distribution of the pine classes is explained by environmental variables, and these distributions differ from classic distribution maps. Hybrid ancestry was biased toward lodgepole pine; however, gene flow between the two species was equal. The results of this study suggest that the hybrid zone is complex and influenced by environmental constraints. As a result of this analysis, range limits should be redefined.
Distribution of Bemisia tabaci (Homoptera: Aleyrodidae) biotypes and their associated symbiotic bacteria on host plants in West Africa
Authors: GNANKINÉ OLIVIER , MOUTON LAURENCE , HENRI HÉLÈNE , TERRAZ GABRIEL , HOUNDETÉ THOMAS , MARTIN THIBAUD , VAVRE FABRICE , FLEURY FRÉDÉRIC
Published: May 2012

Abstract.  1. The whitefly Bemisia tabaci is a pest of many agricultural and ornamental crops worldwide and particularly in Africa. B. tabaci is a complex of more than 20 biotypes. Effective control of B. tabaci calls for a greater knowledge of the local biological diversity in terms of biotypes or putative species. Information is available about biotype distribution in Northern, Eastern, and Southern Africa, but data for Western Africa remain very scarce. At the time of this study, data were available for only three sampling sites in Burkina Faso, where three biotypes have been detected, the native Sub‐Saharan Africa non‐Silver Leafing (AnSL), the Sub‐Saharan Africa Silverleafing (ASL), and the Mediterranean Q biotypes, but no information is available about their respective distributions on host plant species (Gueguen et al., 2010).

2. Our study describes the biotypes and symbiotic bacterial communities of B. tabaci sampled in three West African countries, Burkina Faso, Benin, and Togo. A total of 527 individuals were collected from seven cultivated host plants.

3. In the 20 localities studied, we found the same three biotypes AnSL, ASL, and Q previously detected in Burkina Faso. These biotypes display a specific pattern of geographical distribution influenced by the host plant species. In Benin and Togo, the ASL and AnSL biotypes were predominant, while in Burkina Faso, the Q biotype was dominant, with two sub‐groups, Q1 and Q3 (recorded to date only in this country), and ASL individuals found in sympatry with Q1 individuals in some localities. As previously reported, each biotype and each genetic group harbours a specific community of symbiotic bacteria.
The diagnostic significance of Fourier‐domain optical coherence tomography in Sjögren syndrome, aqueous tear deficiency and lipid tear deficiency patients
Authors: Qiu Xiaodi , Gong Lan , Lu Yi , Jin Huan , Robitaille Mark
Published: May 2012

Purpose:  To determine the role of Fourier‐domain optical coherence tomography (FD‐OCT) in tear meniscus imaging and evaluate its diagnostic significance in Sjögren syndrome (SS), non‐Sjögren’s aqueous tear deficiency (ATD) and lipid tear deficiency (LTD) patients.

Methods:  Two hundred and thirty‐six dry eye patients and 174 healthy controls were enrolled in this study. All subjects were grouped as follows: group A (ATD), group B (LTD), group C (SS) and group D (normal controls). All subjects underwent dry eye questionnaire, FD‐OCT scanning, tear film break‐up time (BUT), corneal fluorescence staining and Schirmer I test (SIT). Tear meniscus height (TMH), tear meniscus depth (TMD) and tear meniscus cross‐sectional area (TMA) were measured using FD‐OCT (RTVue‐100). The area under the receiver operating characteristic curve and the cut‐off point were determined using a logistic regression model.

Results:  Mean TMH, TMD, TMA, BUT and SIT of dry eye patients were significantly lower than those of the controls (p < 0.05). Tear meniscus values were significantly decreased in patients with SS compared with ATD and LTD patients. Tear meniscus values were significantly correlated with clinical examination results in all groups. Accuracy of dry eye diagnosis by FD‐OCT is highest in patients with SS and lowest in LTD patients. The clinical diagnostic critical points were quite different between groups.

Conclusions:  Fourier‐domain optical coherence tomography could provide precise measurement of the tear meniscus with favourable repeatability. Diagnostic significance is more conspicuous in patients with SS. Tear meniscus measurement by FD‐OCT is expected to become a valuable technique in ATD dry eye screening and diagnosis.
Long-run health effects of cost-related non-adherence to prescribed medications among adults in late midlife
Authors: Jensen Gail A , Li Yong
Published: May 2012

Objectives

Sub-optimal adherence to prescribed medications due to cost is known to have adverse health effects over 2–4 years, but little is known about its longer run effects. Here we quantify whether and how cost-related non-adherence (CRN) influences the risk of adverse health events over a 10-year period.

Methods

Nationally representative 1994–2004 data from the Health and Retirement Study, conducted by the US University of Michigan, are analyzed for 2460 adults aged 50–59 years in 1994 who were regularly taking medication(s) and had one or more chronic health conditions at baseline (hypertension, heart disease, diabetes, cancer, lung problems, arthritis or had experienced a heart attack or stroke). Regression models are estimated to quantify CRN's effects on the risk of four different adverse health events, paying careful attention to the potential endogeneity of CRN.

Key findings

Patients who underused medication(s) due to cost are significantly more likely to see new chronic conditions emerge, to be hospitalized, to experience a heart attack or stroke and to see problems develop limiting their ability to work. We also find the more frequent the CRN, the more probable each of these outcomes.

Conclusions

Adults in late midlife with chronic conditions who underuse medications for cost reasons place themselves at much higher risk for serious adverse events over the long run.
Improving type 2 diabetes patients' quality of life by using a community based interactive approach – diabetes mellitus strategy in Yogyakarta, Indonesia
Authors: Hartayu Titien S , Mohamed Izham Mohamed I , Suryawati Sri
Published: May 2012

Objective

The aim of this study was to improve diabetes patients' quality of life (QOL) by using a community based interactive approach – diabetes mellitus (CBIA-DM) strategy.

Methods

This study was a time-series pre and post quasi-experimental with control groups design. Inclusion criteria were adults with type 2 diabetes mellitus (DM), had not attended a diabetes education programme in the last 2 years, were literate and had completed all activities required over the 6-month study period. The intervention group was CBIA-DM and the control groups were DM club and normal care. Data were collected pre, immediately after, 1, 3 and 6 months' post intervention using the World Health Organization QOL–bref (Bahasa Indonesia version) and scored as good, fair and poor. Improvement of QOL was assessed by how much the number of participants at the ‘good’ level increased and was sustained until 6 months' post intervention.

Key finding

The QOL of diabetes patients with can be improved using CBIA-DM strategy (P < 0.05).

Conclusion

Given the WHOQOL–bref usage, such an approach can also be applied for other chronic diseases.
Teachers’ Oral Proficiency in the Target Language: Research on Its Role in Language Teaching and Learning
Authors: Chambless Krista S.
Published: May 2012

In the past decade, the foreign language (FL) profession has established standards for beginning language teachers that are used by accrediting agencies and state licensing agencies to make decisions regarding teacher preparation program recognition and teacher certification. Among these expectations is the requirement that beginning teachers demonstrate a minimum level of Advanced‐Low on the ACTFL Proficiency Guidelines for Speaking. Consequently, the role that teachers’ oral proficiency in the target language (TL) plays in classroom instruction has become a critical issue in the field of FL education. This review presents current research related to teachers’ TL proficiency and its impact on classroom practices, teacher effectiveness, and student learning. The article raises questions that merit investigation in future research as it strives to clarify the role that teacher TL proficiency plays in classroom instruction and learning of the TL.
The performance of robust test statistics with categorical data
Authors: Savalei Victoria , Rhemtulla Mijke
Published: May 2012

This paper reports on a simulation study that evaluated the performance of five structural equation model test statistics appropriate for categorical data. Both Type I error rate and power were investigated. Different model sizes, sample sizes, numbers of categories, and threshold distributions were considered. Statistics associated with both the diagonally weighted least squares (cat‐DWLS) estimator and with the unweighted least squares (cat‐ULS) estimator were studied. Recent research suggests that cat‐ULS parameter estimates and robust standard errors slightly outperform cat‐DWLS estimates and robust standard errors (Forero, Maydeu‐Olivares, & Gallardo‐Pujol, 2009). The findings of the present research suggest that the mean‐ and variance‐adjusted test statistic associated with the cat‐ULS estimator performs best overall. A new version of this statistic now exists that does not require a degrees‐of‐freedom adjustment (Asparouhov & Muthén, 2010), and this statistic is recommended. Overall, the cat‐ULS estimator is recommended over cat‐DWLS, particularly in small to medium sample sizes.
Effect of Tip Clearance Dimensions and Control of Unsteady Flows in a Multi-Stage High-Pressure Compressor
Authors: Gourdain Nicolas , Wlassow Fabien , Ottavy Xavier
Published: May 2012

This paper describes the investigations performed to better understand unsteady flows that develop in a three-stage high-pressure compressor. More specifically, this study focuses on rotor-stator interactions and tip leakage flow effects on overall performance and aerodynamic stability. The investigation method is based on three-dimensional unsteady RANS simulations, considering the natural spatial periodicity of the compressor. Indeed, all information related to rotor-stator interactions can be computed. A comparison is first done with experimental measurements to outline the capacity of the numerical method to predict overall performance and unsteady flows. The results show that the simulation correctly estimates most flow features in the multistage compressor. Then numerical data obtained for three configurations of the same compressor are analyzed and compared. Configurations 1 and 2 consider two sets of tip clearance dimensions and a casing treatment based on a honeycomb design is applied for configuration 3. Detailed investigations of the flow at the same operating line show that the tip leakage flow is responsible for the loss of stability in the last stage. An increase by 30% of the tip clearance dimension dramatically reduces the stable operating range (by 40% with respect to the standard configuration). A modal analysis shows that the stall process in this case involves the perturbation of the flow in the last rotor by upstream stator wakes, leading to the development of a rotating instability. The control device designed and investigated in this study allows for reducing the sensitivity of the compressor to tip leakage flow by recovering the initial stable operating range.
An Educational Software Suite for Teaching Design Strategies for Multistage Axial Flow Compressors
Authors: Bruna Dario , Cravero Carlo , Turner Mark G. , Merchant Ali
Published: May 2012

The T-AXI turbomachinery design system, an axisymmetric methodology recently developed with an educational purpose, has shown great capabilities in the redesign of existing axial flow gas turbine components. Different turbomachines, single or multistage configurations, have been already reproduced with excellent overall performance results: examples are the NASA/GE E3 HP compressor and LP turbine. In this paper, the authors present a detailed analysis of the results of a “case-study” application of the code as a complementary tool to be used during a turbomachinery design course. The NASA/GE E3 HP compressor has been chosen as the test case. Starting from the data available in open literature the different steps of the redesign have been reported: from the flowpath generation through the thermodynamic properties distributions to the overall turbomachine performance analysis. Particular attention has been given to some critical aero design parameters. The links to some interesting and useful literature sources are reported. The free-vortex, the only vortex law included in the first version of the code has been used for a first EEE compressor redesign. Different design vortex methodologies have been implemented in the new release of the code and their effects on the angular momentum are reported. The corresponding geometries can also be interfaced to a mesh generator and then the turbomachinery configurations analyzed by a 3D Navier-Stokes solver. In this way the flow field can be carefully analyzed and the fluid-dynamic physics better understood. With the above software structure the student has the opportunity to test the effects of different design strategies on the turbomachinery performance and to understand the need of a hierarchy of tools that give complete information for the multistage turbomachinery design. Finally, in the last section of the paper, the authors present how a project such as T-AXI, developed from their research activity in turbomachinery, numerical methods and CFD, can be included in the education tool CompEdu.
The Effect of Coolant Injection on the Endwall Flow of a High Pressure Turbine
Authors: Ong Jonathan , Miller Robert J. , Uchida Sumiu
Published: May 2012

This paper presents a study of the effects of two types of hub coolant injection on the rotor of a high pressure gas turbine stage. The first involves the leakage flow from the hub cavity into the mainstream. The second involves a deliberate injection of coolant from a row of angled holes from the edge of the stator hub. The aim of this study is to improve the distribution of the injected coolant on the rotor hub wall. To achieve this, it is necessary to understand how the coolant and leakage flows interact with the rotor secondary flows. The first part of the paper shows that the hub leakage flow is entrained into the rotor hub secondary flow and the negative incidence of the leakage strengthens the secondary flow and increases its penetration depth. Three-dimensional unsteady calculations were found to agree with fast response pressure probe measurements at the rotor exit of a low speed test turbine. The second part of the paper shows that increasing the injected coolant swirl angle reduced the secondary flow penetration depth, improves the coolant distribution on the rotor hub, and improves stage efficiency. Most of the coolant however, was still found to be entrained into the rotor secondary flow.
Influence of Different Rim Widths and Blowing Ratios on Film Cooling Characteristics for a Blade Tip
Authors: Wang Jin , Sundén Bengt , Zeng Min , Wang Qiu-wang
Published: May 2012

Three-dimensional simulations of the squealer tip on the GE-E3 blade with eight film cooling holes were carried out. The effect of the rim width and the blowing ratio on the blade tip flow and cooling performance were revealed. Numerical simulations were performed to predict the leakage flow and the tip heat transfer with the k–ɛ model. For the squealer tip, the depth of the cavity is fixed but the rim width varies to form a wide cavity, which can decrease the coolant momentum and the tip leakage flow velocity. This cavity contributes to the improvement of the cooling effect in the tip zone. To investigate the influence on the tip heat transfer by the rim width, numerical simulations were performed as a two-part study: (1) unequal rim width study on the pressure side and the suction side and (2) equal rim width study with rim widths of 0.58%, 1.16%, and 1.74% of the axial chord (0.5 mm, 1 mm, and 1.5 mm, respectively) on both the pressure side rim and the suction side rim. With different rim widths, the effect of different global blowing ratios, i.e., M = 0.5, 1.0 and 1.5, was investigated. It is found that the total heat transfer rate is increasing and the heat transfer rates on the rim surface (RS) rapidly ascend with increasing rim width.
Influence of Substrate Nature on the Evaporation of a Sessile Drop of Blood
Authors: Brutin David , Sobac Benjamin , Nicloux Céline
Published: May 2012

We fully characterize the natural evaporation of human drops of blood from substrates and substrate-dependent behavior. The heat flux adsorbed by the drops for evaporation is measured by means of a heat flux meter. A side-view measurement enables access to the drop contact angle, wetting diameter, and initial height. A top-view camera allows for the monitoring of the drying regime (deposition, gelation, and fracturation). This directly measured heat flux is related to the evaporative mass flux obtained from the mass of the drop, and the two show good agreement. Both types of measurements indicate that regardless of the substrate type, there is first a linearly decreasing regime of evaporation when the drop is mostly liquid and a second regime characterized by a sharp decrease. We show that the evaporation dynamics are influenced by the substrate’s wettability but not by the substrate’s thermal diffusivity. The different regimes of evaporation exhibited by glass and metallic substrates are explained in terms of evaporation fluxes at the drop surface. In the case of wetting drops (below 40 deg), the evaporation flux is very important along the drop periphery and decreases across the interface, whereas in the case of nonwetting drops (about 90 deg), the evaporation flux is almost uniform across the droplet’s surface. We show that these different evaporation fluxes strongly influence the drying behavior. In the case of metallic substrates, this enables the formation of a uniform "glassy skin" around the droplet surface and, in the case of glass substrates, the formation a skin along the drop periphery with an inward gelation front. This behavior is analyzed in terms of the competition between the drying time and the gel formation time. Unstable drop surfaces were observed at high initial contact angles and are very similar to those of polymer drops.
A New Spectral-Finite Volume Approach in Non-Fourier Heat Conduction Problems With Periodic Surface Disturbances
Authors: Kharati Koopaee Masoud , Omidvar Amir
Published: May 2012

In this study, a simple spectral-finite volume approach for hyperbolic heat conduction problems under periodic surface temperature is presented. In this approach, by choosing only three frequencies from a continuum frequency spectrum of the periodic temperature field, the time dependent governing equation is transformed into the steady state one in the frequency domain. Then, using the finite volume technique, temperature field in the frequency domain for each wave number is obtained. Finally, by transforming back the result to the time domain, the temperature field in the time domain would be obtained. This new method has been validated against some published results and a good agreement has been found. Despite the simplicity of the present method, it is able to accurately predict the temperature distribution in the periodic steady state portion of non-Fourier heat conduction problems subjected to periodic surface temperature.
Delay-Dependent Stabilization of Discrete-Time Systems With Time-Varying Delay via Switching Technique
Authors: Zhang Hui , Shi Yang
Published: May 2012

In this paper, we investigate the stabilization problem of time-delay discrete-time systems with occurrence probabilities for time delays. Using an augmenting technique, we convert random time-delay discrete-time systems to delay-free systems with stochastic variables. We propose to design a sequence of delay-dependent controllers. The implemented controller is chosen according to the measured time delay at each sampling instant. When the delay is randomly time-varying, the implemented controller is switched in a designed controller set. An example is provided to illustrate the effectiveness of the stability condition and another example is offered to show the applicability of the proposed design algorithm.
The Shear-Driven Fluid Motion Using Oscillating Boundaries
Authors: Shakhawath Hossain Md. , Daidzic Nihad E.
Published: May 2012

A classical Stokes’ second problem has been known for a long time and represents one of the few exact solutions of nonlinear Navier-Stokes equations. However, oscillatory flow in a semi-infinite domain of Newtonian fluid under harmonic boundary excitation only leads to fluid wind-milling back and forth in close wall vicinity. In this study, we are presenting the mathematical model and the numerical simulations of the Newtonian fluid and the shear-thinning non-Newtonian blood-mimicking fluid flow. Positive flow rates were obtained by periodic yet nonharmonic oscillatory motion of one or two infinite boundary flat walls. The oscillatory flows in semi-infinite or finite 2D geometry with sawtooth or periodic rectified-sine boundary conditions are presented. Rheological human blood models used were: Power-Law, Sisko, Carreau, and Herschel-Bulkley. A one-dimensional time-dependent nonlinear coupled conservative diffusion-type boundary layer equations for mass, linear momentum, and energy were solved using the finite-differences method with finite-volume discretization. It was possible to test the accuracy of the in-house developed computational programs with the few isothermal flow analytical solutions and with the celebrated classical Stokes’ first and second problems. Positive flow rates were achieved in various configurations and in absence of the adverse pressure gradients. Body forces, such as gravity, were neglected. The calculations utilizing in-phase sawtooth and rectified-sine wall excitations resulted in respectable net flow which stabilizes and becomes quasi-steady, starting from rest, after three to ten periods depending on the fluid rheology. It was assumed that rapid return stroke of the wall actuator resulted in total wall slip while forward wall motion existed with no-slip boundary condition. Shear “driving” and “driven” fluid regions were identified. The shear-thinning fluid rheology delivered many interesting results, such as pluglike flow. Constructive interference of diffusive penetration layers from multiple flat surfaces could be used as practical pumping mechanism in micro-scales.
Sand Transportations and Deposition Characteristics in Multiphase Flows in Pipelines
Authors: Al-lababidi S. , Yan W. , Yeung H.
Published: May 2012

Sand management strategies become an important study to be performed as part of multiphase flow assurance assessments during oil and gas project life and especially for subsea multiphase flow network. This paper presents experimental works to investigate the sand transport characteristics and identify the sand minimum transport condition (MTC) in sand–water and sand–air–water flows in a horizontal and + 5 deg inclined pipelines. The used sand volume fraction, Cv, ranged from 1.61 × 10−5 up to 5.38 × 10−4. The sand minimum transport velocity in single-phase water flow was obtained visually and then compared with that calculated by previous correlations for slurry transport. It was found that in sand–water flow, the pipeline inclination had negligible effect on the minimum sand transport velocity. However, the transport characteristics of sand particles were found changed significantly by changing the pipe inclination, which could result in the change of air–water flow regime. It was observed that sand particles transport more efficiently in terrain slug than stratified wavy flow in +5 deg inclined pipes. The sand transport and settling boundary for different air–water flow regimes were generated for horizontal and +5 deg inclined pipeline.
Optimal Percolation Thresholds of Two- and Three-Dimensional Engineering Composites
Authors: Xu X. Frank
Published: May 2012

Theoretical prediction of percolation thresholds universally applicable for various composites remains a major theoretical challenge. In the work done by Xu (2011, “Ellipsoidal Bounds and Percolation Thresholds of Transport Properties of Composites,” Acta Mech., 223, pp. 765–774), a variational method is developed to predict optimal percolation thresholds for transport properties of three dimensional composites subjected to full dispersion of fillers. In this paper, simplified formulae are provided for engineering applications of 3D composites. New formulae are derived for optimal percolation thresholds of 2D composites, i.e., laminates and thin films, and for composites containing a combination of fillers with different aspect ratios. The effects of dimensionality and waviness are especially discussed.
Dynamic Electromechanical Response of Multilayered Piezoelectric Composites From Room to Cryogenic Temperatures for Fuel Injector Applications
Authors: Shindo Yasuhide , Sasakura Takayoshi , Narita Fumio
Published: May 2012

This paper studies the dynamic electromechanical response of multilayered piezoelectric composites under ac electric fields from room to cryogenic temperatures for fuel injector applications. A shift in the morphotropic phase boundary (MPB) between the tetragonal and rhombohedral/monoclinic phases with decreasing temperature was determined using a thermodynamic model, and the temperature dependent piezoelectric coefficients were obtained. Temperature dependent coercive electric field was also predicted based on the domain wall energy. A phenomenological model of domain wall motion was then used in a finite element computation, and the nonlinear electromechanical fields of the multilayered piezoelectric composites from room to cryogenic temperatures, due to the domain wall motion and shift in the MPB, were calculated. In addition, experimental results on the ac electric field induced strain were presented to validate the predictions.
Consistent Asymptotic Expansion Multiscale Formulation for Heterogeneous Column Structure
Authors: Wang Dongdong , Xie Pinkang , Fang Lingming
Published: May 2012

A consistent asymptotic expansion multiscale formulation is presented for analysis of the heterogeneous column structure, which has three dimensional periodic reinforcements along the axial direction. The proposed formulation is based upon a new asymptotic expansion of the displacement field. This new multiscale displacement expansion has a three dimensional form, more specifically, it takes into account the axial periodic property but simultaneously keeps the cross section dimensions in the global scale. Thus, this formulation inherently reflects the characteristics of the column structure, i.e., the traction free condition on the circumferential surfaces. Subsequently, the global equilibrium problem and the local unit cell problem are consistently derived based upon the proposed asymptotic displacement field. It turns out that the global homogenized problem is the standard axial equilibrium equation, while the local unit cell problem is completely three dimensional which is subjected to the periodic boundary condition on axial surfaces as well as the traction free condition on circumferential surfaces of the unit cell. Thereafter, the variational formulation and finite element discretization of the unit cell problem are discussed. The effectiveness of the present formulation is illustrated by several numerical examples.
Thermal and Mechanical Response of a Carbon Fiber Reinforced Composite to a Transverse Impact and In-Plane Pulsed Electromagnetic Loads
Authors: Barakati A. , Zhupanska O. I.
Published: May 2012

Thermal and mechanical response of a carbon fiber polymer matrix composite plate subjected to a transverse impact and in-plane pulsed electromagnetic loads is studied. Heat transfer analysis in the electrified composite plate for the electric currents of various waveforms (direct current (DC), alternating current (AC), and pulsed) is conducted, and the effects of the waveform parameters (characteristic time, peak, etc.) on the current-induced heating in the composite are investigated. The results show that pulsed electric currents cause significant temperature rises only in the regions immediately adjacent to the electric contact (composite-electrode interface). As for the mechanical response of the composite plate, it is found that the characteristics of the electromagnetic field (waveform, duration of application, and intensity) can significantly reduce deflection and stresses in the plate, and concurrent application of a pulsed electromagnetic load can effectively mitigate the effects of the impact load in the electrically conductive composites.
Modified Stoney's Formulas for Small-Scaled Bilayer Systems
Authors: Liu Dongying , Chen Weiqiu
Published: May 2012

The mechanics of a small-scaled bilayer film-substrate system subject to temperature variation is studied. The modified couple stress theory is employed to take account of the size effects that are usually observed in small-scaled structures. In addition, the effect of weak bonding between the film and substrate is examined by using a linear slip-type model. Exact solutions are derived and the closed-form expressions for residual thermal stress and curvature of the system are given. Modified Stoney’s formulas are also presented for the bilayer system with perfect interface or imperfect interface between the film and the substrate.
An Inflow Method for Axisymmetric Turbulent Boundary Layers Along Very Long Slender Cylinders
Authors: Jordan Stephen A.
Published: May 2012

Generating acceptable inflow conditions for the turbulent boundary layer (TBL) growth along long thin cylinders is a challenging task. Previous production methods such as rescale/recycling, artificial turbulence, and antecedent databases are difficult to implement because the downstream physics do not conform to consistent scaling laws. An alternate inflow approach that involves only recycling the fluctuating elements coupled with a dynamic form of Spalding’s relationship for assigning the mean quantities shows promise for spatially resolving the axisymmetric turbulence along the thin cylinder. Applying this inflow technique for resolving the turbulent scales along a flat plate at a tested momentum-based Reynolds number of Reθ = 670 showed excellent agreement with the experimental data as well as the analytical results from the momentum-integral method. A minor adjustment length of approximately two inflow TBL thicknesses was necessary to attain consistent streamwise growth of the boundary layer as well as a simultaneous reduction of the skin friction. Unlike the flat plate, implementing the inflow technique for the thin cylinder required a feedback mechanism during the early transition phase to capture the downstream realistic turbulence. This initial process invoked downstream evaluation of the three parameters that comprise Spalding’s relationship that were periodically fed upstream to the inflow boundary. The validation test case (Reθ = 620) showed excellent agreement with the experimental measurements in terms of the radial profiles (in cylinder wall units) of the streamwise mean and the normal Reynolds stress. Both the adjustment and turbulence de-correlation axial lengths were under two boundary layer thicknesses from the inlet boundary. Given a useful inflow technique for the thin cylinder permits much needed numerical investigations to complement the present scarcity in the experimental evidence and address numerous unknown characteristics of the TBL spatial growth.
A Device for the Automated Loading and Detection of Brachytherapy Elements Using Nonmechanical Methods for use in Prostate Cancer Treatment
Authors: Proffitt Jason A. , Ball Aaron K.
Published: May 2012

Within the recent resurgence of brachytherapy as treatment for prostate cancer, many new devices have been conceived in the preparation of surgical brachytherapy equipment. Specifically, this work encompasses the automated preparation of preloaded surgical brachytherapy applicators or “needles” through the loading of radioactive seed elements and benign spacer elements. While traditionally a manual operation, current device methodology in this application revolves around semi-automatic mechanical interaction within the element loading procedure. Mechanical interaction can subject elements to damage, specifically seed elements due to thin metallic construct. Damage to elements within a loading system can result in failure of the performed brachytherapy treatment causing potential harm to the patient. Hesitancy in acceptance of these mechanical separation element loading devices can be attributed to the failure nature of these devices. This work seeks to solve the current issue of element damage through noninteraction while offering improvement through full automation of the loading procedure.