bluuebunny/crossref_metadata_2025 huggingface dataset:
Resolving the Democracy Paradox
Authors: Fallon Kathleen M. , Swiss Liam , Viterna Jocelyn
Published: May 2012

Increasing levels of democratic freedoms should, in theory, improve women’s access to political positions. Yet studies demonstrate that democracy does little to improve women’s legislative representation. To resolve this paradox, we investigate how variations in the democratization process—including pre-transition legacies, historical experiences with elections, the global context of transition, and post-transition democratic freedoms and quotas—affect women’s representation in developing nations. We find that democratization’s effect is curvilinear. Women in non-democratic regimes often have high levels of legislative representation but little real political power. When democratization occurs, women’s representation initially drops, but with increasing democratic freedoms and additional elections, it increases again. The historical context of transition further moderates these effects. Prior to 1995, women’s representation increased most rapidly in countries transitioning from civil strife—but only when accompanied by gender quotas. After 1995 and the Beijing Conference on Women, the effectiveness of quotas becomes more universal, with the exception of post-communist countries. In these nations, quotas continue to do little to improve women’s representation. Our results, based on pooled time series analysis from 1975 to 2009, demonstrate that it is not democracy—as measured by a nation’s level of democratic freedoms at a particular moment in time—but rather the democratization process that matters for women’s legislative representation.
Accounting for Women’s Orgasm and Sexual Enjoyment in College Hookups and Relationships
Authors: Armstrong Elizabeth A. , England Paula , Fogarty Alison C. K.
Published: May 2012

This article investigates the determinants of orgasm and sexual enjoyment in hookup and relationship sex among heterosexual college women and seeks to explain why relationship sex is better for women in terms of orgasm and sexual enjoyment. We use data from women respondents to a large online survey of undergraduates at 21 U.S. colleges and universities and from 85 in-depth interviews at two universities. We identify four general views of the sources of orgasm and sexual enjoyment—technically competent genital stimulation, partner-specific learning, commitment, and gender equality. We find that women have orgasms more often in relationships than in hookups. Regression analyses reveal that specific sexual practices, experience with a particular partner, and commitment all predict women’s orgasm and sexual enjoyment. The presence of more sexual practices conducive to women’s orgasm in relationship sex explains some of why orgasm is more common in relationships. Qualitative analysis suggests a double standard also contributes to why relationship sex is better for women: both men and women question women’s (but not men’s) entitlement to pleasure in hookups but believe strongly in women’s (as well as men’s) entitlement to pleasure in relationships. More attention is thus given to producing female orgasm in relationships.
How I Became a Relational Economic Sociologist and What Does That Mean?
Authors: Zelizer Viviana A.
Published: May 2012

My paper proposes the concept of relational work to explain economic activity. In all economic action, I argue, people engage in the process of differentiating meaningful social relations. For each distinct category of social relations, people erect a boundary, mark the boundary by means of names and practices, establish a set of distinctive understandings that operate within that boundary, designate certain sorts of economic transactions as appropriate for the relation, bar other transactions as inappropriate, and adopt certain media for reckoning and facilitating economic transactions within the relation. I call that process relational work. After identifying specific elements of a relational work approach, the paper focuses on the case of monetary differentiation. It compares a relational work theory of earmarking money with behavioral economics’ individually based mental accounting approach.
Relational Work and Economic Sociology
Authors: Bandelj Nina
Published: May 2012

This paper attempts to clarify the concept of relational work for understanding economic life as proposed by Viviana Zelizer. To do so, it first compares the concept to similar notions used in other disciplinary fields. Second, it reinterprets some exemplary economic sociology studies by using the relational work lens to clarify the concept’s utility for empirical analysis. Third, it speculates about the place of relational work in the theoretical toolkit of economic sociologists, in particular its relation to embeddedness. The paper concludes by arguing for the utility of the concept to integrate structural, cultural, and power-focused analyses of economic life, to highlight the often-overlooked role of emotions in economic exchange, and to ground an alternative to rational action theory in economic sociology.
One Woman Helping Another
Authors: Haylett Jennifer
Published: May 2012

California is the global hub for assisted reproductive technology practices, including egg donation. The rise of egg donation in the United States is surprising given the cultural context linking genetics and motherhood and rejecting the commodification of reproduction. Scholars in the hostile worlds camp have grappled with the relationship between intimacy and economics, yet employing this theory to explain the increase in egg donation is unsatisfactory. The concept of relational work, developed by Viviana Zelizer, provides scholars with a robust analytical tool to account for the rise in egg donation. This paper analyzes the relational work of egg donors and fertility center staff. I argue that donors and staff construct an understanding of egg donation that avoids directly challenging the cultural context mentioned above. Analyzing egg donation as a case of relational work demonstrates the need to move beyond the reciprocity/market dichotomy upheld by the hostile worlds framework.
Waltzing, Relational Work, and the Construction (or Not) of Collaboration in Manufacturing Industries
Authors: Whitford Josh
Published: May 2012

The article uses a case study of relationships in American manufacturing industries to demonstrate the utility of documenting the “relational work” that managers do as they negotiate circumstances where either roles or norms are ambiguous. It shows that the explicit identification of the role that relational work plays in those relationships story militates for—and extends, improves upon, and arguably completes—a particular understanding of what economic sociologists should mean when they talk about the “embedding” of the economic in social relations. The article hence shows the utility of jointly using otherwise disparate perspectives in the analysis of interorganizational relationships, and thus contributes to the development of a more unified paradigm in economic sociology.
Agency Input as a Policy-Making Tool
Authors: Villalobos José D.
Published: May 2012

This study posits a theoretical framework for understanding the role and value of agency input in presidential-legislative policy making. The author asserts that by using agency input for policy development, presidents instill their proposals with a degree of bureaucratic objectivity, expertise, process transparency, and agency support, which aids their legislative passage while lowering the extent of changes made to policy substance in the process. To test his hypotheses, the author conducts binary and ordered logistic regression analyses using pooled cross-sectional data across 12 administrations from 1949 to 2010. The author finds that agency input serves as a key component for increased presidential-legislative success.
Caring for Grandparents With Alzheimer’s Disease
Authors: Hamill Sharon Boland
Published: May 2012

This study examined adolescent grandchildren’s contributions to caregiving for grandparents with Alzheimer’s disease. It was predicted that grandchildren would provide more care when parents experienced greater burden, and when adolescents had higher quality relationships with parents and grandparents. It was also hypothesized that these factors would predict higher levels of social commitment and more positive attitudes toward the provision of long-term care. Twenty-nine adolescents and their parents participated in the telephone interview study. Adolescents rated the amount of care they provided to grandparents, relationship quality with grandparents and parents, social responsibility, and attitudes toward the provision of long-term care. Parents reported levels of caregiver burden. Results indicated that grandchildren provided more help when parents provided more care and when grandchildren had greater affection for grandparents. Adolescent grandchildren exhibited lower levels of social responsibility and more negative attitudes toward the provision of long-term care when fathers experienced higher subjective burden.
A Pilot Study of a Weekend Retreat Intervention for Family Survivors of Homicide
Authors: Tuck Inez , Baliko Beverly , Schubert Christine M. , Anderson Lorraine
Published: May 2012

Homicide causes negative unintended consequences for family survivors. Family survivors face complicated grief and overwhelming loss with minimal support from others. The authors offered a retreat intervention as a way to ameliorate the effects of the homicidal death for family survivors of homicide. An exploratory longitudinal pilot study examined the feasibility and acceptability of the intervention and explored the impact of the TOZI© Healing intervention on participants’ distress symptoms. Eight family members participated in the 2-day retreat and completed surveys at five time intervals over 30 months. Descriptive statistics and correlations were used to analyze the data. Although sample sizes were too small to achieve statistical significance, changes on selected holistic health outcomes, supported by overwhelmingly positive focus group responses to the intervention, affirm the need for further study.
The Meaning and Use of Spirituality Among African American Women Living With HIV/AIDS
Authors: Dalmida Safiya George , Holstad Marcia McDonnell , DiIorio Colleen , Laderman Gary
Published: May 2012

The purpose of this qualitative study was to explore the meaning and use of spirituality among African American (AA), predominantly Christian women with HIV. A nonrandom sample of 20 AA women from a large infectious disease clinic in Metro-Atlanta participated in the study. The study used focus groups and individual interviews to interview women about their lived spiritual experience. Content analysis and NUDIST software were used to analyze transcripts. The findings revealed the spiritual views and practices of AA women with HIV. The following themes (and subthemes) emerged: Spirituality is a process/journey or connection (connection to God, higher power, or spirit and HIV brought me closer to God), spiritual expression (religion/church attendance, prayer, helping others, having faith), and spiritual benefits (health/healing, spiritual support, inner peace/strength/ability to keep going, and here for a reason or purpose/a second chance). Findings highlight the importance of spirituality in health and well-being among AA women with HIV/AIDS.
Snail Controls the Mesenchymal Phenotype and Drives Erlotinib Resistance in Oral Epithelial and Head and Neck Squamous Cell Carcinoma Cells
Authors: Dennis Miranda , Wang Guanyu , Luo Jie , Lin Yuan , Dohadwala Mariam , Abemayor Elliot , Elashoff David A. , Sharma Sherven , Dubinett Steven M. , St. John Maie A.
Published: May 2012

Objective

The presence of regional metastases in patients with head and neck squamous cell carcinoma (HNSCC) is a common and adverse event associated with poor prognosis. The authors’ recent work on human HNSCC tissues underlies Snail’s role as a molecular prognostic marker for HNSCC. Snail positivity is significantly predictive of poorly differentiated, lymphovascular invasive, and regionally metastatic tumors. Here, the authors investigate the capacity of Snail to drive epithelial‐mesenchymal transition (EMT) in human oral epithelial cell lines and its ability to confer drug resistance.

Study Design

Snail was overexpressed in HNSCC and oral epithelial cell lines. Anchorage independent growth assays, wound healing assays, invasion and migration assays, spheroid modeling, and cell survival assays were performed.

Setting

Academic tertiary medical center.

Subjects and Methods

Snail overexpressing HNSCC (OSC, Tu212, Tu686) and oral epithelial cell lines (HOK 16‐B, OKF‐6) were evaluated using assays for wound healing, invasion and migration, 3‐dimensional growth, Western blot, and immunofluorescence.

Results

The overexpression of Snail in human HNSCC and oral epithelial cell lines drives EMT. The transfection of Snail confers the expression of a mesenchymal molecular signature, including downregulation of the epithelial adherens, such as E‐cadherin and β‐catenin, and induction of mesenchymal markers. Snail‐overexpressing cell lines demonstrate rapid growth in Anchorage‐independent growth assays, a decreased capacity to form tight spheroids, an increased resistance to erlotinib, and an increased capacity for invasion.

Conclusion

Snail controls the mesenchymal phenotype and drives erlotinib resistance in HNSCC cells. Snail may prove to be a useful marker in predicting epidermal growth factor receptor inhibitor responsiveness.
Management Outcomes of Facial Nerve Tumors
Authors: Channer Guyan A. , Herman Björn , Telischi Fred F. , Zeitler Daniel , Angeli Simon I.
Published: May 2012

Objectives

Primary facial nerve tumors (FNTs) present in varying ways. In this study, the authors present their institutional experience with the management of facial nerve tumors, including their recommendations for available therapies such as observation, microsurgical decompression or removal, and stereotactic radiation. They emphasize the auditory and facial nerve function outcomes.

Study Design

Retrospective case review.

Setting

Tertiary referral center.

Subjects and Methods

Retrospective review of all cases of FNT seen at the authors’ tertiary care academic medical center over a 10‐year period (2002‐2011). The clinical presentation, treatment modality, and outcome parameters of cochlear and facial nerve function were assessed.

Results

Twelve patients were identified. House‐Brackmann grades on presentation were 4 grade I, 2 grade II, 2 grade III, 1 grade IV, and 3 grade V, with 2 grade V patients declining to grade VI shortly after presentation. Seven patients presented with serviceable hearing and 4 with nonserviceable hearing. Treatment options/arms included observation with serial clinicoradiological review (2 cases), stereotactic radiation with the CyberKnife (3 cases), wide fallopian canal decompression (3 cases), microsurgical excision and repair (3 cases), and biopsy followed by observation (1 case). At the end of the review period, facial nerve function was stable in 8 patients, improved in 3, and declined in 1, and none had documented worsening of hearing based on American Academy of Otolaryngology—Head and Neck Surgery Foundation classification.

Conclusions

Management of FNT is largely based on the clinicoradiological picture. Each treatment arm is different, but overall auditory and facial function can be maintained.
Angelman Syndrome Due to a Termination Codon Mutation of the UBE3A Gene
Authors: Al-Maawali Almundher , Machado Jerry , Fang Ping , Dupuis Lucie , Faghfoury Hannaneh , Mendoza-Londono Roberto
Published: May 2012

Angelman syndrome is a neurodevelopmental disorder characterized by global developmental delay, mental retardation, seizures, microcephaly, and severe speech delay. It may be caused by deletion of chromosome region 15q11.2 of the maternally inherited chromosome, mutations in the UBE3A gene, uniparental disomy, or imprinting defects. Most patients with this diagnosis have a severe phenotype, and a few have a mild form of the disease. We report a patient with a novel mutation in the UBE3A gene that consists of a deletion of the termination codon (c.2556-*+6del GTAAAACAAA) and results in an elongated protein E3 ubiquitin–protein ligase. Our patient has a mild phenotype compared with other patients in general and specifically to patients with UBE3A mutations. He has mild developmental delay, moderate speech delay, and no seizures. Recognition of this genotype–phenotype correlation will allow better genetic counseling to other patients with similar stop codon mutations.
Infantile-Onset Alexander Disease
Authors: Ramesh Konanki , Sharma Suvasini , Kumar Atin , Salomons Gajja S. , van der Knaap Marjo S. , Gulati Sheffali
Published: May 2012

Alexander disease is an autosomal dominant leukoencephalopathy characterized by developmental delay, macrocephaly, and characteristic neuroimaging abnormalities predominantly involving frontal lobes. We report a 6-year-old Indian boy with infantile-onset Alexander disease, who has an unusually mild clinical course and a de novo p.Leu359Val mutation in the glial fibrillary acidic protein gene.
Splenic Artery Aneurysm Rupture
Authors: Khurana Jasjit , Spinello Irene M.
Published: May 2012

Splenic artery aneurysm (SAA) is the most common (60%) of all visceral artery aneurysms. The majority of these cases are asymptomatic, but the presentation of their rupture can vary from abdominal/chest pain to cardiovascular collapse (Sadat U, Dar O, Walsh S, Varty K. Splenic artery aneurysms in pregnancy—a systematic review. Int J Surg. 2008;6(3):261-265.). Although rare, the mortality associated with the rupture is as high as 25% (De Vries JE, Schattenkerk ME, Malt RA. Complications of splenic artery aneurysm other than intraperitoneal rupture. Surgery. 1982;91(2):200-204; Caillouette JC, Merchant EB: Ruptured splenic artery aneurysm in pregnancy. Twelfth reported case with maternal and fetal survival. Am J Obstet Gynecol 1993;168(6 Pt 1):1810-1811) and increases to 75% among pregnant women with a concomitant fetal mortality of 95% (O’Grady JP, Day EJ, Toole AL, et al. Splenic artery aneurysm rupture in pregnancy. A review and case report. Obstet Gynecol. 1977; 50(5):627-630). Because of such high maternal and fetal mortality prompt management of SAAs is of utmost importance. We are presenting a case of a 35-year-old woman with a missed ruptured SAA who after an emergent cesarean section went into profound shock and was unable to be resuscitated. This case illustrates the importance of considering the diagnosis of SAA rupture in hemodynamically unstable peripartum females.
Characteristics of Patients With the “Malignant Obesity Hypoventilation Syndrome” Admitted to an ICU
Authors: Marik Paul E. , Desai Himanshu
Published: May 2012

Background:

The incidence of obesity in westernized nations is increasing at an alarming rate. We have noted an increasing number of patients admitted to our intensive care unit (ICU) with hypercapnic respiratory failure and multisystem organ dysfunction related to obesity. We have coined the term the malignant obesity hypoventilation syndrome (MOHS) to describe this entity.

Methods:

We reviewed the hospital records of all patients who were admitted to our ICU over an 8-month period, with a body mass index (BMI) greater than 40 kg/m2 and a PaCO2 greater than 45 mm Hg. We excluded patients with musculoskeletal disease, intrinsic lung disease, and those with >20 pack-year smoking history.

Results:

Sixty-one patients (8% of all admissions) met the inclusion criteria for our study. The patients’ mean BMI was 48.9 ± 8.6 kg/m2. The patients’ mean age was 59 ± 11; 47 (77%) were female and 56 (92%) were black. All patients were admitted to the ICU with hypercapnic respiratory failure. The patients had been admitted to our hospital on average 6 times over the previous 2 years; 75% had been erroneously diagnosed and treated for chronic obstructive pulmonary disease (COPD)/asthma and 86% had been treated with diuretics for congestive cardiac failure. All patients had type 2 diabetes and the metabolic syndrome. Three patients had a tracheotomy in place at admission and required mechanical ventilation. All of the remaining patients were treated with noninvasive bilevel positive airway pressure (BiPAP), with 23 patients failing BiPAP and requiring mechanical ventilation. Seven patients had a tracheotomy performed. On the basis of unexplained abnormalities of liver function tests, 39 patients (64%) were presumptively diagnosed with nonalcoholic steatohepatitis (NASH). Pulmonary function tests were suggestive of a restrictive pattern in all patients tested. By echocardiography 43 (71%) patients had left ventricular hypertrophy and 37 (61%) patients had features of left ventricular diastolic dysfunction. Forty-seven (77%) patients had pulmonary hypertension, which was moderate to severe (pulmonary systolic pressure >45 mm Hg) in 25 cases. All patients had an elevated C-reactive protein (9.4 ± 6.9 mg/dL), and all but 1 were vitamin D deficient (13.5 ± 8.5 ng/mL). Eleven patients (18%) died during the index hospitalization.

Conclusions:

MOHS is a serious multisystem disorder with a high mortality that appears to be relatively common, frequently misdiagnosed, and inadequately treated.
Educator Assessment
Authors: Hanna Patricia Lavon , Allen Ann
Published: May 2012

This analysis examines Arizona’s English fluency evaluation initiative, which aims to address the fluency standards for teachers of English Language Learners (ELLs) set forth in the 2001 No Child Left Behind Act. The authors deploy a sociolinguistic framework to consider what components of teachers’ language are being evaluated by the policy, illuminating how the policy conflates fluency, accent, and pronunciation. After determining that the initiative does in fact evaluate teachers based on accent, the authors argue that Arizona’s unique interpretation of NCLB’s fluency standard exceeds Congressional intent and has no foundation in the professional standards for teachers of ELLs as established by either the National Council of Teacher Accreditation (NCATE) or the Teachers of English to Speakers of Other Languages organization (TESOL). The authors then interrogate the initiative and the evaluation protocol, discussing implications on the development of democratic school communities, language-based discrimination, and the academic experiences of ELLs. Concluding that the initiative and protocol fail to evaluate fluency, threaten democratic school communities, and risk discriminatory practices, the authors recommend that Arizona revoke the initiative and return teachers affected by the policy to the ELL classrooms for which they were initially hired.
From ‘Amor Fati’ to ‘disgust’: Affect, habitus, and class identity in Didier Eribon’s Retour à Reims
Authors: Lane Jeremy F.
Published: May 2012

In his Retour à Reims (2010), Didier Eribon draws on the sociology of Pierre Bourdieu and on his own earlier work on gay identity to offer a moving and insightful account of his social trajectory and of the issues of class, education and sexual identity that trajectory raises. Throughout this autobiographical account, Eribon stresses the centrality of affect and emotion to social and sexual identity, and the feelings of shame, disgust, frustration and rejection that marked his and his parents’ relationship to their working-class identity. In so doing, he draws on two different and potentially contradictory theoretical traditions: Eve Sedgwick’s work on shame and queer identity and Bourdieu’s emphasis on the centrality of affect to the workings of the class habitus. This article examines the tensions or potential contradictions between these two traditions, questioning, in particular, Bourdieu’s insistence on the immediate, pre-reflexive way in which working-class subjects allegedly invest in and come to love their social identity and destiny. Focusing on those episodes in Retour à Reims which suggest that Eribon’s parents had a far more contradictory relationship to working-class identity than Bourdieu’s theory would suggest, the article calls for a reformulation of certain of the key tenets of Bourdieusian sociology. This involves drawing on the work of Maurice Merleau-Ponty as a means of thinking through the mind–body dualism that underpins Bourdieu’s concept of habitus. The article concludes that the work of Beverley Skeggs on class and gender offers a more fruitful way of theorising the relationships between class, affect, social identity and political or social change.
Réponses et principes
Authors: Eribon Didier
Published: May 2012

This article replies to points made by other authors in this volume, notably on the negative role of psychoanalysis in queer debates, and in a restated defence of gay marriage and the sociological approach to individual subject formation. Drawing on the analysis of the ‘social unconscious’ to be found in Retour à Reims, it then seeks to sketch out the bases for ‘critical thought’ in the current cultural and political context, parameters formed by ‘determinism’ (a structural understanding of the lived reality of an unequal social world) and ‘immanence’ (the presence and availability of that world to agency and change).
A minimax sensor placement approach for damage detection in composite structures
Authors: Vanli O Arda , Zhang Chuck , Nguyen Annam , Wang Ben
Published: May 2012

This article proposes a new method for optimal placement of sensors for detecting damages in composite structures. The problem is formulated as a minimax optimization in which the goal is to find the coordinates of a given number of sensors so that the worst (maximum) probability of nondetection of the sensor network is made as good as possible (minimized). It is shown that a minimax approach can more efficiently place the sensors on complex geometries, compared to existing placement methods that consider average probability of detection. The method allows one to account for characteristics of sensors by assuming that the effectiveness of a sensor decreases with the distance from damage via an experimentally determined sensor probability of detection function and sensor noise in sensor network optimization. The formulation also enables to account for nonuniform likelihood of damages on the structure, which often arises due to irregular loading or boundary conditions, using a damage probability density. Numerical examples and an experimental validation study involving a Lamb-wave sensing system are presented to show the effectiveness of the proposed method.
Analysis of nonlinear free vibration and damping of a clamped–clamped beam with embedded prestrained shape memory alloy wires
Authors: Rezaei DA Hojjat , Kadkhodaei Mahmoud , Nahvi Hassan
Published: May 2012

Nonlinear free vibration and damping of a clamped–clamped composite beam containing shape memory alloy wires with different prestrains embedded in the midsurface are investigated. The constitutive relations of shape memory alloy are considered in the large deflection response of the elastic Euler–Bernoulli beam, and Hamilton’s principle is used to derive differential equation of the beam motion with extensible midplane. Considering midplane stretching due to tension in the shape memory alloy wires provides an ability to model damping in a nonlinear analysis although there is no distinct damping expression in the governing equation of motion. The results show a gradual decrease in the free vibration amplitude of the beam until it reaches a fully elastic response while this cannot be seen in linear models. Free vibrations of the beam are investigated, and time response, phase diagram, state of stress and strain in the wires, and variations of loss factor are studied. The effect of prestrain in the shape memory alloy wires on the final stable vibration amplitude and loss factor in free vibrations of the beam is also investigated.
Dynamic mechanical properties of an electrorheological fluid under large-amplitude oscillatory shear strain
Authors: Mohammadi Farough , Sedaghati Ramin
Published: May 2012

In the present study, the shear stress response and the dynamic mechanical properties of an electrorheological fluid are experimentally investigated for small/large shear strain amplitude at moderate range of frequencies and different field intensities. A new efficient constitutive model has also been proposed, which can accurately predict the measured experimental data. Compared with the Fourier transformation rheology, the proposed model requires less number of parameters in order to predict the stress response and the mechanical properties, including storage and loss moduli for different strain amplitudes, frequencies, and field intensities. This leads to simplify the parameter identification in order to predict the material response using the optimization methods.
Vibration control of plates through hybrid configurations of periodic piezoelectric shunts
Authors: Casadei Filippo , Beck Benjamin S , Cunefare Kenneth A , Ruzzene Massimo
Published: May 2012

Periodic arrays of hybrid-shunted piezoelectric actuators are used to suppress vibrations of an aluminum plate over broad frequency bands. Commonly, piezoelectric-shunted networks are used for individual mode control, through tuned, resonant resistive/inductive circuits, and for broadband vibration attenuation, through negative impedance converters. Periodically placed resonant shunts allow for broadband reduction resulting from the attenuation of propagating waves in frequency bands which are defined by the spatial periodicity of the array and by the shunting parameters considered on the circuit. Such attenuation typically occurs at medium–high frequencies, while negative impedance converter networks are effective in reducing the vibration amplitudes of the lower modes of the structure. In this article, the combination of periodic resonant shunts and negative impedance converter networks on the same aluminum panel is studied to verify the possibility of combining the advantages of the two concepts. Both numerical and experimental investigations demonstrate that broadband attenuation is achieved in the mid–high frequency regimes due to the presence of resistive/inductive networks, while the combination with negative impedance converter circuits is responsible for amplitude reduction of the full frequency spectrum. Numerical simulations and frequency response measurements on a plate demonstrate that an attenuation region of about 1000 Hz is achieved with a maximum 8 dB vibration reduction.
Multi-objective optimal control of vibratory energy harvesting systems
Authors: Scruggs Jeff T , Cassidy Ian L , Behrens Sam
Published: May 2012

This article examines the use of actively controlled electronics to maximize the energy harvested from a stationary stochastic disturbance. In prior work by the authors, it has been shown that when the harvester dynamics are linear and the transmission losses in the electronics are resistive, the optimal feedback controller is the solution to a nonstandard linear-quadratic-Gaussian optimal control problem. This article augments the theory in the following three distinct ways: (a) It illustrates how to use linear matrix inequalities to balance the objective of energy harvesting against other response control objectives (such as minimum requirements on closed-loop damping and maximum levels of voltage response), in the synthesis of the optimal feedback law; (b) it establishes a more realistic characterization of the transmission losses in the actively controlled power electronics used to regulate the extraction of power; and (c) it illustrates how the optimal control theory for resistive loss models can be extended to accommodate the more realistic loss models. The theory is illustrated in the context of a piezoelectric energy harvesting model, and an example is used to illustrate that the theory can be used to simultaneously optimize the feedback law, together with the switching frequency and storage bus voltage of the power electronics.
On the performance of a dual-mode non-linear vibration energy harvesting device
Authors: Ramlan Roszaidi , Brennan Michael J , Mace Brian R , Burrow Stephen G
Published: May 2012

The research trend for harvesting energy from the ambient vibration sources has moved from using a linear resonant generator to a non-linear generator in order to improve on the performance of a linear generator; for example, the relatively small bandwidth, intolerance to mistune and the suitability of the device for low-frequency applications. This article presents experimental results to illustrate the dynamic behaviour of a dual-mode non-linear energy-harvesting device operating in hardening and bi-stable modes under harmonic excitation. The device is able to change from one mode to another by altering the negative magnetic stiffness by adjusting the separation gap between the magnets and the iron core. Results for the device operating in both modes are presented. They show that there is a larger bandwidth for the device operating in the hardening mode compared to the equivalent linear device. However, the maximum power transfer theory is less applicable for the hardening mode due to occurrence of the maximum power at different frequencies, which depends on the non-linearity and the damping in the system. The results for the bi-stable mode show that the device is insensitive to a range of excitation frequencies depending upon the input level, damping and non-linearity.
Study of corrugated disc rotary damper based on intelligent effect
Authors: Chen Shumei , Shi Wei
Published: May 2012

An experimental rotary damper device with a corrugated disc and a plate disc (called corrugated damper) has been examined. The narrow gap between the two discs is filled with an electrorheological fluid (or magnetorheological suspension); therefore, the electrostructural effect has to be taken into consideration. Computational fluid dynamics (FLUENT software) is used to produce comparative performance data between corrugated rotary damper and ordinary dual-plate rotary damper. Theoretical and numerical studies have shown that the total output torque increment for the corrugated disc rotary damper is significantly larger than that of the dual-disc rotary damper when the impact of the electric field strength is ignored. The results help the optimal design of a pre-prototyping structure with an electrorheological (or magnetorheological suspension) fluid damper.
Effect of heat treatment on the two-way recovery stress of tube-shaped NiTi
Authors: Yoo Young Ik , Jeong Ju Won , Lee Jung Ju , Lee Chang Ho
Published: May 2012

The effect of annealing temperatures on the thermomechanical behavior of NiTi in terms of transformation temperatures, mechanical properties, two-way shape memory strain, and two-way recovery stress was investigated experimentally to develop a NiTi tubular actuator with high two-way recovery force. Five tubular specimens were used to obtain the two-way shape memory strain and two-way recovery stress by varying heat treatment conditions. Annealing heat-treated temperatures were 400°C, 500°C, 600°C, 700°C, and 800°C. A two-way shape memory effect was introduced in the shape memory alloy tube by thermomechanical treatment after annealing heat treatment. According to the results, the two-way strain induced by shape memory cycling was independent of the annealing temperature. However, the two-way recovery stress generated by the two-way strain depended on the annealing temperature, even though the values of the two-way strain were similar in all specimens. Considering all heat treatment results, we concluded that the optimum annealing temperature to acquire two-way recovery stress and two-way strain for an actuator is 600°C.
NiTi Belleville washers: Design, manufacturing and testing
Authors: Maletta Carmine , Filice Luigino , Furgiuele Franco
Published: May 2012

The thermomechanical properties of nickel–titanium-based Belleville washers have been analyzed in this investigation, together with their unusual mechanical and functional features, which can be attributed to the reversible phase transformation mechanisms of nickel–titanium alloys. In particular, numerical simulations have been carried out for a preliminary design of the Belleville washer, using a commercial finite element software and a special constitutive model for shape memory alloys. Subsequently, Belleville washers have been manufactured from a commercial pseudoelastic nickel–titanium alloy, by disk cutting and a successive shape setting by a thermomechanical treatment. Finally, the thermomechanical response of the washers, in terms of isothermal force–deflection curve and thermal cycles between phase transition temperatures, has been experimentally analyzed. The results highlighted a marked effect of the temperature on the characteristic curve, as well as good recovery capabilities under both mechanical and thermal cycles. In addition, nickel–titanium Belleville washers exhibit a marked hysteretic behavior, as a consequence of the hysteresis in the stress–strain response of the alloy. Thanks to these features, nickel–titanium Belleville washers can be used as smart elastic elements, that is, with tunable stiffness and damping properties, as well as solid-state actuators, due to their recovery capabilities.
Fabrication of a novel laser-processed NiTi shape memory microgripper with enhanced thermomechanical functionality
Authors: Daly Matthew , Pequegnat Andrew , Zhou Yunhong N , Khan Mohammad I
Published: May 2012

The thermomechanical properties of nickel-titanium shape memory alloys have sparked significant research efforts seeking to exploit their exotic capabilities. Until recently, the performance capabilities of nickel-titanium devices have been inhibited by the retention of only one thermomechanical response. In this article, the application of a novel laser-processing technique is demonstrated to create a monolithic self-positioning nickel-titanium shape memory microgripper. Device actuation and gripping maneuvers were achieved by thermally activating processed material regions which possessed unique phase transformation onset temperatures and thermomechanical recovery characteristics. The existence of each thermomechanical material domain was confirmed through differential scanning calorimetry analysis. Independent thermomechanical recoveries of each embedded shape memory were captured using tensile testing methods. Deployment of each embedded shape memory was achieved using resistive heating, and in situ resistivity measurements were used to monitor progressive phase transformations.
Active and semi-active control of structures – theory and applications: A review of recent advances
Authors: Casciati Fabio , Rodellar José , Yildirim Umut
Published: May 2012

It is internationally recognized that structural control was introduced in civil engineering through a pioneering article by Yao and through the implementations promoted by Kobori. The concepts of active and semi-active structural control in civil and infrastructure engineering date back 40 years and much progress has been recorded during these four decades. Periodically, state-of-the-art manuscripts have been published and technical books were also printed to testify the maturation of the topic. This article only covers the period from the second semester of 2009 to the first semester of 2011, emphasizing the developments in terms of theoretical, numerical and experimental studies, as well as the use of control algorithms and devices in actual implementations. It is observed that there are still several operational limitations to prevent from the expected growth of the applications in standard design. Nevertheless, some innovative concepts help to foresee future developments within special sectors of applications.
Magnetorheological damper—an experimental study
Authors: de-J Lozoya-Santos Jorge , Morales-Menendez Ruben , Ramirez-Mendoza Ricardo , Tudón-Martinez Juan C , Sename Olivier , Dugard Luc
Published: May 2012

A magnetorheological damper is evaluated under exhaustive experimental scenarios, generating a complete database. The obtained database includes classical tests and new proposals emphasizing the frequency contents. It also includes the impact of the electric current fluctuations. The variety of the performed experiments allows us to study the magnetorheological damper force dynamics. A brief description of the damper behavior and a categorization of experiments based on driving conditions and target applications on vehicle dynamics are discussed. The identification of two magnetorheological damper models and their cross validation emphasize the importance of the persistence of experimental inputs and the combinations of rod displacement and electric current sequences for better modeling. New findings in design of experiments for model identification are presented.
Enhanced stochastic, subharmonic, and ultraharmonic energy harvesting
Authors: Lin Ji-Tzuoh , Walsh Kevin , Alphenaar Bruce
Published: May 2012

Nonlinear bistable systems have been shown to provide improved efficiency for harvesting energy from random and broadband vibration sources. This article explores the distinct frequency response in the broadened spectrum of a particular nonlinear energy harvester, a piezoelectric cantilever with magnetic coupling. The cantilever response evolves dynamically with frequency around the main cantilever resonance. Both stochastic and multifrequency vibration responses are observed and account for some of the improved efficiency. In addition, subharmonics and ultraharmonics of the main resonance, along with various combinations of these, appear. An analytical model of the bistable dynamics produces results consistent with those observed experimentally. Overall, four distinct types of efficiency improvements appear, in which the signal is amplified above the noncoupled cantilever response: (a) ultraharmonic amplification below resonance frequency, (b) stochastic amplifications in multifrequency and multiamplitude oscillations, (c) ultrasubharmonic amplification, and (d) subharmonic amplification. Taken together, the stochastic, subharmonic, and ultraharmonic responses produce an average of threefold to fivefold increase in voltage production.
Environmental Policy and Political Realities
Authors: Zivin Joshua Graff , Damon Maria
Published: May 2012

Effective environmental policymaking requires an understanding of how environmental goals interact with other political goals. This article analyzes development strategies in the PICT’s, where policymakers aim to leverage tuna resources into sustainable economic development and job creation. The authors develop a model that analyzes costs and benefits of different development strategies, with a focus on job creation and local socioeconomic factors that drive optimal policy mixes across PICTs. The analysis demonstrates that investment in fisheries management can effectively encourage economic development and create employment opportunities, and compare this strategy to others such as selling access permits and investing in processing capacity. While many benefits of fisheries management are widely recognized, its ability to create high-quality employment opportunities is often overlooked. For many PICTs, this may represent the lowest cost strategy for jobs creation and, coupled with selling fishery access to foreign vessels, can form a strong basis for economic development plans.
The Growth Machine Stops? Urban Politics and the Making and Remaking of an Edge City
Authors: Phelps Nicholas A.
Published: May 2012

Critical reflections on growth machine and urban regime theory have pointed to the value of integrating these theories of urban politics with the likes of regulation theory. This article attempts such a synthesis with a view to further elaborating theories of urban politics with regard to settlement type and evolution. The scheme presented is prompted by a critical questioning of how the seeming novelty of edge cities can obscure rapid change in settlements that have already passed through several cycles of redevelopment and may have experienced associated shifts in urban politics. The empirical basis of the article is a case study of Tysons Corner, Virginia—perhaps the archetypal “edge city”—and contemporary deliberations over its future development. An edge city like Tysons Corner has been the focus for the suburban ‘growth machine’ driving the urbanization of the United States but may now be the subject of distinctly postsuburban political dynamics that resemble a developmental regime. In conclusion the author notes both the wider analytical challenges posed by and the policy significance of any such changes in urban politics.
Homeownership and Civic Engagement in Low-Income Urban Neighborhoods
Authors: Manturuk Kim , Lindblad Mark , Quercia Roberto
Published: May 2012

This paper tests whether there is a causal relationship between homeownership and two forms of civic engagement. We explore three theoretical linkages between homeownership and civic engagement: financial self-interest, the dwelling as a bundle of interests, and residential mobility. Using a sample of lower-income homeowners and a matched sample of renters, we analyze data on neighborhood group membership, social activity, homeownership status, and mobility over a 4-year period. Findings indicate that renters who became homeowners during the study period were no more involved in neighborhood organizations prior to homeownership than renters who did not become homeowners. However, involvement increased significantly after these renters became homeowners. We discuss the implications of this finding for policies aimed at promoting homeownership in lower-wealth urban neighborhoods.
The Pregnant Patient With Congenital Heart Disease
Authors: Ortman Amy J.
Published: May 2012

Advances in the surgical palliation and correction of congenital heart lesions have improved survival and increased the number of patients living into adulthood. Although pregnancy outcomes will be favorable for most patients with congenital heart disease, the cardiovascular challenges associated with pregnancy and delivery are best managed with a multidisciplinary approach during the puerperium. This review addresses the prevalence, physiology, risk assessment, peripartum complications, and anesthetic management of the pregnant patient with underlying congenital heart disease.
Boys and their teeth
Authors: Drummond Murray , Drummond Claire
Published: May 2012

This is a paper based on qualitative focus group interviews with 33 boys in early childhood (ages 5 to 7). The basis of the interviews was originally to understand the way in which boys come to perceive issues around masculinities, physical activity, sport and health. However, given the naturalistic manner of qualitative focus group interviews, additional themes were uncovered around boys’ understanding of oral health, in particular the relationship between their teeth and health. At an age where the boys are gaining increasing levels of autonomy in terms of personal hygiene and individual health it appears that dental health is being neglected. The need to address this concern through developing functional health literacy is imperative for boys at this age. Schools are the ideal site in which such an initiative can occur with concomitant knowledge transferred back to the family home.