bluuebunny/crossref_metadata_2025 huggingface dataset:
A new temperature-dependent modulus model of glass/epoxy composite at elevated temperatures
Authors: Guo Zhan-Sheng , Feng Jiemin , Wang Hui , Hu Hongjiu , Zhang Junqian
Published: November 2012

Temperature-dependent modulus of glass fiber/epoxy composite laminates was studied at temperatures ranging from room temperature up to 120℃. The storage modulus, loss modulus, loss factor, and glass transition temperature of two layer-up composite laminates were investigated by dynamic mechanic analysis. Static flexural modulus was also measured by control force mode in dynamic mechanic analysis. A new and simple temperature-dependent model both for the dynamic storage modulus and static flexural modulus was developed. This model depends only on one parameter which has specific physical meaning. The model prediction showed excellent agreement with our own experimental results over the full range of transition region. Furthermore, comparing our model’s prediction and other experimental data of many types of composites, which were studied by other researchers, we point to the fact that our model can be applied to many different polymer matrix composites.
Experimental and numerical analysis of pinned-joints composite laminates: Effects of stacking sequences
Authors: Khashaba UA , Sebaey TA , Mahmoud FF , Selmy AI , Hamouda RM
Published: November 2012

The present study investigates the effect of stacking sequence on the failure loads (strength) and modes of pinned-joints glass-fiber reinforced epoxy composite laminates. Specimens with [0/90]2S, [15/−75]2S, [30/−60]2S and [45/−45]2S stacking sequences were investigated both experimentally and numerically. A series of ASTM tests were performed on unidirectional [8]0 glass-fiber reinforced epoxy composite laminate to determine the properties of the single lamina that was needed for the finite element analysis. A 3D progressive damage model was built with the aid of ABAQUS software, failure criteria and property degradation rules to simulate the problem. The results showed that the [0/90]2S laminate has the highest ultimate strength. The minimum bearing and ultimate strength was observed for [30/−60]2S laminate. Loading the specimens up to the ultimate value lead to shear-out failure mode for [0/90]2S, [15/−75]2S and [30/−60]2S stacking sequences, while specimens with [45/−45]2S stacking sequence are characterized by bearing failure mode. The experimental and numerical results agree well with a maximum Euclidean error norm of 8.57%.
Hostile to Hierarchy? Individuality, Equality and Moral Boundaries in Dutch Class Talk
Authors: van Eijk Gwen
Published: November 2012

Cultural class analysts point to the hidden and morally loaded nature of class in explaining people’s ambivalence towards class and their position in the class hierarchy. This article examines the way in which Dutch respondents draw on cultural repertoires about equality and individuality to deny or flatten class hierarchy and individualize class differences. The equality ideal reverberates in the uncoupling of socio-economic differences from moral boundaries. The study shows that higher-educated respondents in particular construct a class hierarchy based on education. Interpreting cultural boundaries in terms of education is conducive to moral evaluations and hierarchalization. Drawing cultural boundaries in terms of taste is not conducive to hierarchalization. The study shows that notions of individuality, through individualizing class positions, work to both deny and conceal class differences in relation to cultural resources. In addition, the study shows the relevance of cultural class analysis for Dutch sociology and society.
The Global Financial Crisis and Individual Distress: The Role of Subjective Comparisons after the Collapse of the Icelandic Economy
Authors: Ragnarsdóttir Berglind Hólm , Bernburg Jón Gunnar , Ólafsdóttir Sigrún
Published: November 2012

Sociologists have emphasized that abrupt social changes can evoke subjective deprivation that can create subjective injustice and emotional distress. The global economic crisis offers an opportunity to examine this issue. This article builds on relative deprivation theory and proposes that economic crises evoke three subjective comparisons that influence distress: comparisons to 1) past outcomes; 2) the situation of others; and 3) expected future outcomes. Using a national survey obtained during the economic crisis in Iceland, we examine how these comparisons influence subjective injustice and emotional distress (anger and depression). Results indicate that perceived reduction in the standard of living has a more pronounced effect on subjective injustice and anger, 1) when individuals think that the crisis has harmed them more than others; and 2) when they have negative expectations about their future. The study implies that subjective comparisons can moderate the effect of sudden social change on distress.
Boys Will Be Boys … Won’t They? Change and Continuities in Contemporary Young Working-class Masculinities
Authors: Roberts Steven
Published: November 2012

This article contributes to the literature concerning the construction of working-class masculine identity in a context of unprecedented social transformation. Drawing on qualitative interviews with 24 young men currently employed in the retail sector, this study finds that contrary to much research on masculinities young working-class men are able to resist dominant and hegemonic cultural ideals. The respondents demonstrate a very different attitude towards the ‘emotional labour’ required in the service sector than is often documented, while also rejecting notions of traditional gendered domestic responsibilities in respect of their futures as potential partners and parents. Congruent with other emerging research in this area, the reference point for an ‘acceptable’ masculine identity appears to have shifted, with some young working-class men’s lives, at least, illustrating an attenuated or softened version of masculinity.
Expecting Motherhood? Stratifying Reproduction in 21st-century Scottish Abortion Practice
Authors: Beynon-Jones Siân M
Published: November 2012

This article illustrates how Scottish health professionals involved in contemporary abortion provision construct stratified expectations about women’s reproductive decision-making. Drawing on 42 semi-structured interviews I reveal the contingent discourses through which health professionals constitute the ‘rationality’ of the female subject who requests abortion. Specifically, I illustrate how youth, age, parity and class are mobilised as criteria through which to distinguish ‘types’ of patient whose requests for abortion are deemed particularly understandable or particularly problematic. I conceptualise this process of differentiation as a form of ‘stratified reproduction’ (Colen, 1995; Ginsburg and Rapp, 1995) and argue that it is significant for two reasons. Firstly, it illustrates the operation of dominant discourses concerning abortion and motherhood in 21st-century Britain. Secondly, it extends the forms of critique which feminist scholarship has developed, to date, of the regulation of abortion provision in the UK.
Characterization of textile fabrics under various thermal exposures
Authors: Mandal Sumit , Song Guowen , Ackerman Mark , Paskaluk Stephen , Gholamreza Farzan
Published: November 2012

This study explores the behavior of textile fabrics under thermal exposures. The performance of thermal protective textile fabric systems with different structural features was evaluated under laboratory simulated thermal exposures. The study demonstrated that the protective performance of textile fabric systems varies with different types of thermal exposure. To provide effective protection in flame and radiant-heat exposures, the most important fabric properties to address are emissivity, absorptivity and thermal resistance. In hot surface exposures, the compression property of the fabric systems is the primary feature to consider for protection. Hot water and steam exposures produce mass transfer through fabrics. In the presence of water or steam jet pressure, fabric compression is a primary factor in protecting the human body. The findings obtained in this study can be used to engineer fabric systems that provide better protection from various thermal exposures.
Effects of Self-Affirmation on Daily Versus Occasional Smokers’ Responses to Graphic Warning Labels
Authors: Zhao Xiaoquan , Peterson Emily B. , Kim Wonsun , Rolfe-Redding Justin
Published: November 2012

There is growing evidence that self-affirmation can reduce defensive processing of threatening health messages among high risk individuals. However, how self-affirmation might influence low risk individuals is less clear. This study examined the effect of self-affirmation on daily versus occasional smokers’ reactions to graphic on-pack warning labels. Results showed a relatively consistent pattern of interaction wherein self-affirmation decreased favorable reactions to the warning labels among occasional smokers, whereas its effect on daily smokers was mostly nonsignificant. Potential explanations of these findings are offered and their practical implications are discussed.
Learning in Health Care Organizations and Systems
Authors: Touati Nassera , Denis Jean-Louis , Roberge Danièle , Brabant Brigitte
Published: November 2012

This article presents, through the example of health care systems, a theoretically founded analysis of learning processes in the context of reform implementation. Following a critical assessment of the two most prominent approaches to knowledge management—mechanistic and organic—we propose another approach, which consists in coordinating the learning of interdependent actors. The potential of this approach is illustrated through an empirical case study of the implementation of a Quebec program to combat cancer.
Perceptions of Authority
Authors: Tomsich Elizabeth A. , Guy Mary E.
Published: November 2012

Public officials are vested with authority of the state, and institutions such as courts crystallize this blend of formal power and relational dynamics. We probe how gender affects the interpretation of authority by using simulations of traffic court. Observers evaluated the professional demeanor of the judge. Results indicate that judge gender makes a difference in how professionalism is rated, gender of the citizen makes a difference in how emotive expression is interpreted, and the interaction of judge and citizen gender affects how the judge’s communication is evaluated. We conclude that gender contextualizes power by moderating its perception and interpretation.
Governing Codes
Authors: Crozier Michael P.
Published: November 2012

In recent decades, Western democratic governments have encountered coordination challenges in the face of increasing levels of complexity. This article examines how the widespread penetration of new information and communication technologies is implicated in this situation. Attention is drawn to how information is no longer just a resource but also a generative power. While the new informational dynamics entail greater capacities for instrumental manipulation, they are also recursive and produce emergent effects. These new dynamics introduce a novel set of coordination and control challenges that mark a significant departure from industrial modes of governance and organization.
Development of a finite differential model for the analysis of environmental effects on transmission lines for down-hole applications
Authors: Christidis Konstantinos , Gunarathne Gunti PP , Peteineri Kalliopi
Published: November 2012

Coaxial cables are often used for data-transmission between top-side and down-hole tools over long distances. In term of cost, it is advantageous to use the same cables for power transmission when feasible. However, environmental effects can degrade the performance of cables, which are exposed to hostile conditions. This paper examines the environmental effects on transmission efficiency of coaxial cables when used for the transmission of power to down-hole tools and data acquisition systems. The performance of the cables was analysed using a finite differential model. A special feature of the model is that it implicitly introduces the effects of temperature differentials to which the cable may be exposed, through the primary cable constants. The model can be used to predict the optimum condition for maximum power transfer in the low-to-medium frequency range.
Stigma and Status
Authors: Lucas Jeffrey W. , Phelan Jo C.
Published: November 2012

This article explicates and distinguishes the processes that produce status orders and those that produce stigmatization. It describes an experimental study in which participants were assigned interaction partners before completing a task where they had opportunities to be influenced by the partners and opportunities to socially reject the partners. Results show clear influence effects of educational attainment and mental illness but no effects for physical disability. Social distance effects are present for mental illness and physical disability but not for educational attainment. Results additionally show that stigmatizing attributes combine with task ability in affecting influence and also suggest that task ability may reduce social rejection. These results indicate that stigmatizing attributes combine with status markers in a way similar to previously studied status attributes. The findings extend traditions of research on status and stigma while also having potentially important implications for strategies to reduce inequalities based on mental illness.
Fall risk six weeks from onset of stroke and the ability of the Prediction of Falls in Rehabilitation Settings Tool and motor function to predict falls
Authors: Nyström Anna , Hellström Karin
Published: November 2012

Objective:

To investigate whether the Prediction of Falls in Rehabilitation Settings Tool (Predict FIRST) and motor function could be used to identify people at risk of falling during the first six weeks after stroke, and to compare the risk of falling according to Predict FIRST with real falls frequency.

Design:

A longitudinal, prospective study.

Patients:

Sixty-eight people newly diagnosed with stroke admitted to an acute stroke unit.

Methods:

The participants underwent an assessment of motor ability (Modified Motor Assessment Scale according to Uppsala University Hospital version 99 (M-MAS UAS-99)) and falls risk (Predict FIRST) on the first to fourth day at the acute stroke unit. Falls occurring in the acute stroke unit were recorded and falls occurring after discharge were reported by telephone follow-up. The prediction of falls was analysed with binary logistic regression.

Results:

Fourteen of the patients (21%) fell at least once during the first six weeks after stroke. The strongest significant predictor for falls was a high score on Predict FIRST (odds ratio 5.21, confidence interval (CI) 1.10–24.78) followed by M-MAS UAS-99 parts C–E (odds ratio 0.65, CI 0.44–0.95). Predict FIRST underestimated the risk of falling as the median fall risk was 9% according to Predict FIRST.

Conclusion:

Although Predict FIRST has the ability to predict falls in people with recent onset of stroke, there is some underestimation of fall risk.
Efficacy of Lacosamide as Adjunctive Therapy in Children With Refractory Epilepsy
Authors: Yorns William R. , Khurana Divya S. , Carvalho Karen S. , Hardison H. Huntley , Legido Agustín , Valencia Ignacio
Published: November 2012

Lacosamide is a US Food and Drug Administration (FDA)–approved antiepileptic drug for patients 17 years or older with partial epilepsy. There are sparse data on children. The objective of our study was to evaluate its efficacy/safety in children with refractory epilepsy. Forty children (mean age 14.3 years) were treated with lacosamide at our institution (adjunctive therapy in 36, monotherapy in 4). Fifteen patients had symptomatic focal epilepsy, 2 had cryptogenic focal epilepsy, 20 had symptomatic generalized epilepsy, and 3 had cryptogenic generalized epilepsy. Two had juvenile myoclonic epilepsy and 5 had Lennox-Gastaut syndrome. Forty-two percent had at least >50% reduction in seizure frequency, and 6 became seizure free. Average dose was 7 mg/kg/d and average follow-up was 9.2 months. Responders had a 76.5% mean decrease in seizures. Fifteen children experienced an adverse reaction and 7 discontinued lacosamide (4: Ineffective, I: insurance denial, 1: tremor, 1: behavior). Lacosamide is effective and well-tolerated in children with refractory epilepsy.
A Comparative Study of Primary and Secondary Stereotypies
Authors: Ghosh Debabrata , Rajan Prashant V. , Erenberg Gerald
Published: November 2012

This study compares primary stereotypies (repetitive, self-stimulating, and seemingly nonsensical movements that can occur within typically developing children) and secondary stereotypies (those occurring within autistic or mentally retarded children). Utilizing a retrospective chart review from 1995 to 2010, the current study compares primary and secondary stereotypies by the application of a classification system that organizes the movement by its type (motor only, phonic only, mixed) and complexity. In addition, it investigates other parameters associated with the movements such as duration, frequency, age, functional impairment, and progression. The sample group consisted of 28 primary and 28 secondary cases. Primary stereotypies were predominantly motor, simple, of shorter duration, and of less frequency, whereas secondary stereotypies had more vocalization, complexity, longer durations, and higher frequencies. Moreover, functional impairment due to stereotypies was noted in 3 primary and 7 secondary cases, and worsening of stereotypies was noted in 70% of primary versus 44% of secondary cases.
Prevention of Traumatic Brain Injury in Youth and Adolescents
Authors: Barnes Vernon A. , Maria Bernard L. , Caldwell Alice Little , Hopkins Irene
Published: November 2012

The goal of this project was to promote bicycle helmet use via an inpatient educational program. We hypothesized that this program would increase bicycle helmet use. One hundred twenty inpatients with history of regular (>1 time per week) bicycle riding (mean age 10.0 ± 3.6 years; 67 males, 53 females; 57 whites, 59 blacks, 4 other) were randomized to treatment (n = 58) or control (n = 62) groups. All participants received a bicycle helmet. At 1 month, 50 (92.6%) of the intervention group and 48 (82.8%) of the control group wore a helmet every bike ride ( P < .07). At 3 months, 50 (96.2%) of the intervention group and 44 (80%) of the controls wore a helmet with every bike ride ( P < .03). The study proved feasible, requiring trained personnel to deliver the intervention. Providing a helmet without the intervention was effective in 80% to 83% of cases with respect to parental report of helmet wearing compliance.
Early Spinal Cord and Brainstem Involvement in Infantile Leigh Syndrome Possibly Caused by a Novel Variant
Authors: Tenney Jeffrey R. , Prada Carlos E. , Hopkin Robert J. , Hallinan Barbara E.
Published: November 2012

Leigh syndrome, due to a dysfunction of mitochondrial energy metabolism, is a genetically heterogeneous and progressive neurologic disorder that usually occurs in infancy and childhood. Its clinical presentation and neuroimaging findings can be variable, especially early in the course of the disease. This report presents a patient with infantile Leigh syndrome who had atypical radiologic findings on serial neuroimaging studies with early and severe involvement of the cervical spinal cord and brainstem and injury to the thalami and basal ganglia occurring only late in the clinical course. Postmortem microscopic examination supported this timing of injury within the central nervous system. In addition, mitochondrial deoxyribonucleic acid sequencing showed a novel homoplasmic variant that could be responsible for this unique lethal form of Leigh syndrome.
Effects of Miglustat on Stabilization of Neurological Disorder in Niemann–Pick Disease Type C
Authors: Karimzadeh Parvaneh , Tonekaboni Seyed Hassan , Ashrafi Mahmoud Reza , Shafeghati Yousef , Rezayi Alireza , Salehpour Shadab , Ghofrani Mohammad , Taghdiri Mohammad Mehdi , Rahmanifar Ali , Zaman Talieh , Aryani Omid , Shoar Babak Najaf , Shiva Farideh , Tavasoli Alireza , Houshmand Massoud
Published: November 2012

Niemann–Pick disease type C is a rare neurodegenerative disorder with autosomal recessive inheritance that can be broadly categorized into different forms dependent on age at disease onset: pre-/perinatal, early infantile, late infantile, juvenile, and adolescent/adult. This study was conducted to define the age at onset, clinical manifestations, neuroimaging findings and response to treatment in 21 patients diagnosed with Niemann–Pick disease type C and managed in the neurology departments of hospitals in Tehran, Iran. The effects of miglustat on patient ambulation, fine and gross motor function, swallowing, hearing, speech, seizures, psychomotor development, and ocular movements were evaluated for up to 26 months of treatment. Ambulation, fine and gross motor movements, swallowing, speech, and supranuclear gaze palsy were generally stabilized during therapy, and psychomotor delay appeared to be improved in early- and late-infantile onset patients. However, miglustat had no effect on organomegaly or other systemic manifestations of the disease. Miglustat was well tolerated.
Atypical Face Processing in Children With Tuberous Sclerosis Complex
Authors: Jeste Shafali Spurling , Hirsch Suzanna , Vogel-Farley Vanessa , Norona Amanda , Navalta Mary-Clare , Gregas Matt C. , Prabhu Sanjay P. , Sahin Mustafa , Nelson Charles A.
Published: November 2012

There is a high incidence of autism in tuberous sclerosis complex. Given the evidence of impaired face processing in autism, the authors sought to investigate electrophysiological markers of face processing in children with tuberous sclerosis complex. The authors studied 19 children with tuberous sclerosis complex under age 4, and 20 age-matched controls, using a familiar–unfamiliar faces paradigm. Of the children, 6 with tuberous sclerosis complex (32%) had autism. Children with tuberous sclerosis complex showed a longer N290 latency than controls (276 ms vs 259 ms, P = .05) and also failed to show the expected hemispheric differences in face processing. The longest N290 latency was seen in (1) children with autism and tuberous sclerosis complex and (2) children with temporal lobe tubers. This study is the first to quantify atypical face processing in children with tuberous sclerosis complex. This functional impairment may provide insight into a mechanism underlying a pathway to autism in tuberous sclerosis complex.
Hyperekplexia
Authors: Chan Keung Kit , Cherk Sharon Wan-wah , Lee Hencher Han-chih , Poon Wing Tat , Chan Albert Yan-wo
Published: November 2012

Hyperekplexia is a rare neurologic disorder, characterized by excessive startle response to unexpected stimuli. There are 3 cardinal features: generalized stiffness immediately after birth that normalizes during the first year of life; excessive startle reflex to unexpected (particularly auditory) stimuli; and a short period of generalized stiffness following the startle response while patient cannot elicit voluntary movements. Awareness of this condition will avoid misdiagnosis of disorders like epilepsy. Clonazepam is an effective medical treatment. We report a patient whose frequent falls triggered by sudden noise or tactile stimuli was initially misdiagnosed as epilepsy. The clinical diagnosis was subsequently revised to hyperekplexia and confirmed by mutation analysis of the GLRA1 gene, which showed c.497G>C (p.Cys166Ser) and c.526delG (p.Asp176Metfs*16). Both of them are novel mutations. His response to clonazepam is dramatic and has been able to engage in sports and social activities.
Judges on Trial
Authors: Johnson Brian D.
Published: November 2012

Extant research on the effects of judicial background characteristics suggests minimal influence from the race or gender of the sentencing judge in criminal cases. This raises at least two possibilities: (1) the combined influence of judicial recruitment, indoctrination, and socialization into the judgeship results in a homogenous body of criminal court judges; or (2) current approaches to identifying judge effects in criminal sentencing have methodological and conceptual flaws that limit their ability to detect important influences from judicial background characteristics. The current article examines this issue with data from the Pennsylvania Commission on Sentencing that is augmented to include information on sentencing judges and criminal court contexts. It argues that the mode of conviction shapes the locus of sentencing discretion in ways that systematically underestimate judge effects for pooled estimates of incarceration and sentence length. The empirical results support this interpretation, especially for incarceration in trial cases, where older, female, and minority judges are substantially less likely to sentence offenders to jail or prison terms. The article concludes with a discussion of future research directions and policy implications for judge effects and disparity in sentencing.
Comparing Stewardship Across Faith-Based Organizations
Authors: Schneider Jo Anne
Published: November 2012

Nonprofits theory on the role of organizational context focuses on generalizing principles such as neoinstitutionalism and institutional isomorphism. Organizational culture theory focuses on internal organizational culture, ignoring the larger community culture that influences nonprofit behavior. Relying on anthropological understandings of culture as comprising both the values and symbols of a community and its structures and practices, this article describes three support systems for faith-based nonprofits that come out of founding religious traditions. Using comparative case studies across 81 faith communities and FBOs in the United States, research suggests that systems are generalizable across religions and localities, but they come out of specific religious cultures adapted to fit the U.S. system.
Children’s bricolage under the gaze of teachers in sociodramatic play
Authors: Tam Po Chi
Published: November 2012

Drawing on the theory of dialogism and the literature on children’s culture and cultural resistance, this article investigates the contextual and textual features of the cultural making of a group of children in sociodramatic play in a Hong Kong kindergarten. Different from other, similar studies, this study reports that under the gaze of the teacher, children’s play is largely practised as a reproduction of the teacher’s cultural texts. Children’s culture or resistance only arises as a bricolage of various cultural texts in which the cultural texts of the teacher and the children are intertwined, dissonant and hybridized. Two major modes of bricolage are identified. They are hybridization and invalidation. This result suggests that the teacher’s strategies and authoritarian discourse are suppressive of the children’s culture, aiming largely to shape the way and process of their cultural making. Nonetheless, from the evidence in this study, it is believed that bricoleur is a creative act as it involves tactful and creative appropriation, orchestration and transformation of all sorts of cultural texts which are at hand. The pretend play corner is consequently reframed and recreated as a heteroglot playing space of the children’s own.
Towards a sociology of 10–12 year olds? Emerging methodological issues in the ‘new’ social studies of childhood
Authors: McNamee Sally , Seymour Julie
Published: November 2012

This article reports on an analysis of 320 empirical research articles published between 1993 and 2010 in three of the leading ‘childhood’ journals. The study looked to establish the potential samples used in accounts of empirical research studies with children; and to explore the methodology employed. The first part of this article outlines why a consideration of the ages used in childhood research is worthy of investigation. This addresses technical, methodological and epistemological dimensions of the area. It then goes on to discuss the results of our investigations. The guiding question was ‘who are the children in the social study of childhood?’, and the authors conclude that there is an over-focus on a particular age group.
Competing meanings of childhood and the social construction of child sexual abuse in the Caribbean
Authors: Pasura Dominic , Jones Adele D , Hafner James AH , Maharaj Priya E , Nathaniel-DeCaires Karene , Johnson Emmanuel Janagan
Published: November 2012

This article examines the dynamic interplay between competing meanings of childhood and the social construction of sexual abuse in the Caribbean. Drawing on qualitative data from a study undertaken in six Caribbean countries, the article suggests that Caribbean childhoods are neither wholly global nor local but hybrid creations of the region’s complex historical, social and cultural specificities, real or imagined. As childhood is a concept that lies at the intersection of multiple frames of reference, context-specific definitions of childhood – what it means to be a child – have a direct impact on the way in which the issue of child sexual abuse is constructed and understood.
Friction stir welding parameters optimization of heterogeneous tailored welded blank sheets of aluminium alloys 6061 and 5083 using response surface methodology
Authors: Ghaffarpour Morteza , Dariani Bijan Mollaei , Hossein Kokabi Amir , Razani Nabi Allah
Published: November 2012

Today, tailored welded blank sheets have found various applications in automotive, aeronautic and many other industrial fields. One of the most efficient methods for production of tailored welded blank sheets is application of the friction stir welding process. In the present article, the effect of friction stir welding parameters on the microstructure and mechanical properties of heterogeneous tailored welded blank sheets made from aluminium alloys of types 5083-H12 and 6061-T6 with the similar thickness of 1.5 mm is studied. The considered parameters are rotational speed of the tool, linear speed of the tool, pin diameter and shoulder diameter. In order to come by a tailored welded blank sheet with optimal mechanical properties, response surface methodology, which is considered as a strong tool in design of experiments, has been employed to design the experiment matrix, and the corresponding experiments have been conducted under laboratory conditions. Tensile strength of tailored welded blank sheets are determined as the relation in the mathematical model. The optimal condition and objective effects of parameters are determined via this relation. Data variance analysis showed that rotational speed and diameter tool have the most and the least effect on tensile strength, respectively. Rotational and linear speed are more effective than pin and shoulder diameter in input heat, which is produced by friction.
Fibre Bragg Grating sensor grids for Structural Health Monitoring of the foremast of STS Dar Mlodziezy
Authors: Król A , Majewska K , Mieloszyk M , Murawski L , Ostachowicz W , Weintrit A
Published: November 2012

In this article, a concept of an application for a Fibre Bragg Grating sensor grid for Structural Health Monitoring the foremast of STS Dar Mlodziezy is presented and discussed. Research presented in this article are related to characteristics of the foremast of STS Dar Mlodziezy during her normal operation. The main goal of the research was to determine the strain/stress level of the foremast above the topmast crosstrees where three steel jib stays are mounted. To achieved this goal during the research special attention was paid to setting the sails and to taking in the sails.
A preliminary approach to simulating cyclic variability in a port fuel injection spark ignition engine
Authors: Suyabodha Apiwat , Pennycott Andrew , Brace Chris J
Published: November 2012

Differences in the combustion process from one cycle to the next, termed cyclic variations, are an important feature of spark ignition engines. These variations cause fluctuations in the work output of the engine and can therefore degrade engine and vehicle performance. In addition, the uneven running caused by cyclic variability of combustion constrains the engine operating range and thus has a direct effect on fuel consumption. Existing one-dimensional engine models typically represent cyclic variability using some form of stochastic behaviour defined by a pre-set normal distribution. This approach does not offer an insight into the mechanisms underlying variability, and makes it difficult to include variability when calibrating the engine using simulation. Three-dimensional modelling approaches can offer an insight but are too complex to be used extensively within a calibration exercise.

In this paper, a simple, preliminary approach using empirical functions easily generated using standard engine instrumentation is used to augment a one-dimensional engine model via co-simulation approach to include a representation of the effects of the air–fuel ratio and residual gas fraction on combustion efficiency, early rate of combustion and duration of combustion. These parameters allow the engine model to simulate the effects of deterministic aspects of cyclic variability on heat release, in-cylinder pressure and indicated mean effective pressure.

The model is validated by comparing its prediction of cyclic variability under both rich and lean operation to experimental data. The resulting predictions match experimental results qualitatively and quantitatively. The model can be used to inform subsequent optimization processes, representing the variability-induced constraints on the operating envelope. This will assist in the generation of fuel efficient calibrations and also allow cycle-to-cycle variation effects to be included much earlier in the design process. The model will also aid the development of online control approaches aiming to reduce cycle-to-cycle engine variability.
Research on the global matching relationship between the key components of engine cylinder heads
Authors: Li Baotong , Hong Jun , Yang Rong , Chen Yubao
Published: November 2012

The motivation of this paper is to develop a straightforward approach to provide an optimal solution to cylinder head design. In this research, a topological plot is first defined to represent the load bearing topology of the cylinder head. A simplified model enabling a designer to clearly understand the global matching relationship between the key components of a cylinder head is then identified from the topological plot. After characterizing the stress/strain behavior through parametric analysis, an interesting phenomenon associated with stress convergence in the cylinder head is observed. A concise mathematical explanation for this phenomenon is then derived from the well-known Kuhn–Tucker conditions, leading to a novel optimization criterion for cylinder head design. In this criterion, the optimal solution is described as an ideal “balanced point” among the main design parameters in terms of weight distribution of the key components. The benefits and advantages of the proposed method are finally confirmed by a concrete design case.
Relationships between the heterogeneous microstructure, the mechanical properties and the braking behaviour of an organic brake lining material
Authors: Baklouti Mouna , Elleuch Riadh , Cristol Anne-Lise , Najjar Denis , Desplanques Yannick
Published: November 2012

Industrial brake lining materials are composite with complex formulations consisting of multiple constituents. Resulting from the fabrication process, the morphology and distribution of the constituents have significant influences on the future properties and braking performance. In this study, an in-depth analysis ranging from the microscale to the macroscale was performed to assess the relationships between the microstructure, the mechanical properties and the braking performance of an industrial brake lining material formulated for heavy vehicles. It was observed that the manufacturing process had different effects on the morphology and size of constituents and on their distribution in the phenolic binder. The morphologies of large organic particles such as rubber and graphite were affected by the mixing procedure, contrary to those of fibres and mineral particles. A transverse anisotropy consistent with fibre orientation due to cold preforming and hot moulding was observed. The microstructure displayed a strong local heterogeneity right up to the mesoscopic scale at which friction and wear mechanisms typically occur. The mechanical properties were analysed with regard to the heterogeneity of the microstructure to determine the scale at which these properties could be considered to be associated with a homogenised behaviour. The rubbing surface after braking showed that load-bearing localisation depends on the nature, morphology and orientation of constituents but that this heterogeneity can be of interest with regard to the braking ability.
Evaluation of the efficiency and the drive cycle emissions for a hydrogen direct-injection engine
Authors: Wallner Thomas , Matthias Nicholas S , Scarcelli Riccardo , Kwon Jason C
Published: November 2012

Hydrogen is seen as a sustainable energy carrier for transportation because it can be generated using renewable energy sources and it is a favorable fuel for clean vehicle powertrains. Hydrogen internal-combustion engines have been identified as a cost-effective consumer of hydrogen in the near term to aid in the development of a large-scale hydrogen infrastructure. Current research on hydrogen internal-combustion engines is directed by a series of efficiency and emissions targets defined by the US Department of Energy including a peak brake thermal efficiency of 45% and nitrogen oxide emissions of less than 0.07 g/mile. A high-efficiency hydrogen direct-injection engine was developed at Argonne National Laboratory to take advantage of the combustion characteristics of hydrogen. The engine employs a lean control strategy with turbocharging for power density comparable with that of gasoline engines. The injection strategy was optimized through collaborative three-dimensional computational fluid dynamics and experimental efforts to achieve mixture stratification that is beneficial for both a high efficiency and low nitrogen oxide emissions. The efficiency maps of the hydrogen engine demonstrate a peak brake thermal efficiency of 45.5% together with nitrogen oxide maps showing emissions of less than 0.10 g/kW h in much of the operating regime. In order to evaluate the driving-cycle nitrogen oxide emissions, the engine maps were fed into a vehicle simulation assuming a midsize sedan with a conventional (non-hybrid) powertrain. With a 3.0 l hydrogen engine, nitrogen oxide emissions from a Urban Dynamometer Driving Schedule cycle are 0.017 g/mile which fulfills the project goal and are even sufficiently low to meet the Super-Ultra-Low-Emissions Vehicle II emissions specification. The city or highway fuel economy, normalized to gallons of gasoline, is 32.4/51.5 mile/gal(US) for a combined average of 38.9 mile/gal(US), exceeding the 2016 Corporate Average Fuel Economy standard. Further vehicle simulations were performed to show the effect of engine downsizing. With a smaller 2.0 l engine, nitrogen oxide emissions increase to 0.028 g/mile, which still exceeds the US Department of Energy target together with the benefit of a fuel economy improvement to 45.4 mile/gal(US) (combined).
Transient computational fluid dynamics modelling of the melting process in thermal bonding of porous fibrous media
Authors: Peksen M , Acar M , Malalasekera W
Published: November 2012

A continuum model of the melting process in porous fibrous media is introduced. The fluid flow, heat transfer and phase change within the porous nonwoven web is numerically solved using computational fluid dynamics. Boundary conditions from an experimentally validated whole system model of a typical industrial machine, producing fibrous webs are incorporated. The presented model shows the capability to investigate the phase change during heating of the thermoplastic fibres during nonwoven web formation. Moreover, the fibres’ geometrical information and constitutive equations, describing the material behaviour are included. The approach considers the fibre thickness, sheath fraction, and thermophysical properties like melting temperature, latent heat of fusion and the liquid fraction, enabling the assessment of different fibre types and to determine the properties of the fabric. The model results reveal that the web porosity has the most significant effect on the melting process among the considered parameters. Thermal gradients that occur inside the web are due to the combined convection and latent heat of fusion effect, which stores heat to melt the fibres. The model is applicable to a wide variety of systems ranging from textiles, fibrous beds, ceramics, membranes and porous composite materials.
Modeling the valve dynamics in a reciprocating compressor based on two-dimensional computational fluid dynamic numerical simulation
Authors: Wang Yu , Feng Jianmei , Zhang Bo , Peng Xueyuan
Published: November 2012

This article presents a numerical simulation of the thermodynamic process in the cylinder and dynamics of the self-acting valves for an air reciprocating compressor. The finite-volume method was employed to solve the compressible turbulent flow in the cylinder and through the valves. A single degree-of-freedom model was adopted to simulate the valve dynamics. The piston’s motion was defined by a user’s preset function, and the fluid-structure interaction between the gas flow and the valve dynamics was solved in a strictly coupled fashion. The technique of non-conformal interfaces was adopted to allow fluxes between adjacent zones with different mesh node locations. Based on the analysis of the characteristics of the flow through valves and the valve movement, sensitivity analysis on the valve impact velocity and the angle of inclination indicates that the valve impact velocity was more sensitive to the variation of the rotational speed and the valve lift while severe inclining motion occurs when the valves are installed in the radial direction. Instantaneous gas flow and force coefficients with the variation of valve displacement are also obtained according to the mass-flow rate across the valve and the gas force acting on the ring plate.
Brush seals and labyrinth seals in gas turbine applications
Authors: Aslan-zada Farhad E , Mammadov Vugar A , Dohnal Fadi
Published: November 2012

The overall efficiency of gas turbines is strongly affected by the performance of the sealing arrangement between the stationary and rotary components. Maintaining an accurate clearance during nominal and transient operation and providing effective damping is of key importance for seal designers. The implementation of brush seals as an alternative to labyrinth seals in a gas turbine engine is outlined in this article. A review of published literature is performed to analyze the leakage performance of brush seals and labyrinth seals. The emphasis lies on the importance of an accurate clearance control and the subsequent reduction in parasitic flows. Based on a discussion of the performance and integrity of brush seals in gas turbine applications their advantages over labyrinth seals are highlighted. Some attention is drawn into common drawbacks of brush seals and how these were improved over time to become more competitive and reliable. Finally, advanced concepts, technological aspects of the design of the brush seals influencing their leakage characteristics and future applications prospective are discussed. It was shown that one of the key advantages of brush seals over conventional labyrinth seals is their positive rotordynamic characteristic. The rotordynamic force coefficients demonstrate very low and generally negative cross-coupled stiffness thereby positively affecting the turbomachine operability in industrial gas turbine applications. The review concluded the need for further work on studying rotordynamic behaviour of brush seals operating at conditions more realistic to real engine operation environment in order to complete the understanding of the seal dynamics in real operation condition.
Effects of recessed blade tips on the performance and flow field in a centrifugal compressor
Authors: Jung Yohan , Choi Minsuk , Park Joon-Young , Baek Je Hyun
Published: November 2012

This article presents a numerical investigation of the influence of a recessed blade tip on the performance and flow field in a centrifugal compressor with a vaned diffuser. Steady computations were performed for three different blade tip geometries over their whole operating ranges. A flat tip blade was used as a baseline case to assess two different recessed blade geometries. It was found that recessed blade tip designs could improve the total-to-total pressure ratio and efficiency over whole operating ranges. The recessed tips were also effective in reducing the tip leakage flow. However, the recess cavity had an adverse effect on the efficiency due to the generation of a vortex in the cavity. As a result, the overall stage loss was reduced in the recessed cases because the positive effect of the reduced tip leakage flow ended up being superior to the negative effect of a strong vortex in the cavity. In addition, the diffuser performance of the centrifugal compressor could be enhanced with the recess cavity, because the pressure recovery coefficient was higher in the recessed cases than in the flat tip case. A parametric study was conducted to determine the geometry of a recess cavity with improved performance. This study revealed that as the cavity volume increases, the tip leakage flow continuously decreases but the strength of the cavity vortex increases. Therefore, it may be possible to optimize the recess cavity geometry further.
‘Harry walks, Fabio runs’: A case study on the current relationship between English national identity, soccer and the English press
Authors: Griggs Gerald , Gibbons Tom
Published: November 2012

On 8 February 2012 Fabio Capello resigned from his position as manager of the England men’s national association football (soccer) team. The date this decision became public coincided with the acquittal in court of Harry Redknapp following the Tottenham Hotspur FC manager being accused of tax evasion. As Redknapp was considered the media favourite to succeed Capello as England manager, press coverage of these two events proved an interesting case through which to explore the current relationship between English national identity, soccer and the English national press. As such, this paper is concerned with how the events of that day were reported by nine different English national newspapers across 82 pages of coverage. Thematic analysis revealed that journalists often adopted a ‘Little Englander’ mentality with regards to their attitudes towards Capello, due to his Italian nationality. Contrary to this, the press frequently depicted Redknapp as a typically ‘English’ working-class hero linking him with nostalgic references to a bygone ‘golden era’ of English soccer. These findings illustrate the main ways in which the English press continue to present English national identity via their soccer-related coverage as insular and rooted in the past.