bluuebunny/crossref_metadata_2025 huggingface dataset:
Now You See It and Now You Don't: Consequences of Veiling Relational Work
Authors: KREEGER LISA , HOLLOWAY ELIZABETH
Published: July 2009

This paper offers findings from a study of relationship formation in Information Technology (I.T.) outsourcing services and explores the conditions in which relational practices are veiled by the work designs, tools, business lingo, and even media representations of Information Technology outsourcing services. Veiling describes the way the language and focus of these elements have taken over and permeated organizations to levels where the aspects of relational work are obscured. As a result, relational skills are delegitimized, work is slowed down, conflict results from incorrect assumptions, and inefficient technology is tolerated. We identify intended and unintended consequences, on individuals and organizations, of relational veiling as a strategy that emerges in response to the everyday realities of the workplace.
Contact Lists and Youth
Authors: Yapchaian Matthew
Published: July 2009

This paper explores the nature of networked contact lists in an emerging new media ecology as they relate to a population of 10 American pre‐teens and teens (9–15). Mobile, gaming, and Web 2.0 services are contributing to a shift in the role of the contact list from a static visualization of a database to an active communication tool and the site of sociality. We draw in material from ethnographic research illustrating contact lists as dynamic sites for social activity, existing across multiple media channels, which evolve in time with an individual user. We then describe how contact list use by American youth (9 – 15) produces new understandings of accessibility, sociality, and visibility within the scope of personal relationships, mobility, and play in everyday life. We conclude with how we are informing corporate strategy on youth marketing and new product development.
Beyond Walking With Video: Co‐Creating Representation
Authors: BEAN JONATHAN
Published: July 2009

This paper discusses a method I used to conduct a study ofhygge,a Danish concept that is usually translated as “cosiness.” I wanted to learn more abouthyggeand how it related to technology in the home. The method I used builds on my experience with spatial ethnography, on Bruno Latour's theory of representation, and on the work of visual anthropologist Sarah Pink. I asked participants to use a video or still camera to help me document their home. With participant and researcher both behind the lens of a camera, I saw a significant remapping of the power relationship between researcher and participant; we were able to focus together on the material home as the object of the research. In addition to reducing the time needed to build rapport, this method offers a way to analyze cultural practices such ashyggethat are not entirely visible in the material world.
Video Utterances: Expressing and Sustaining Ethnographic Meaning through the Product Development Process
Authors: CRAMER MEG , SHARMA MAYANK , SALVADOR TONY , BEAUREGARD RUSSELL
Published: July 2009

In this paper we discuss the use of short, specific videos to communicate ethnographic data throughout the product development process. Ethnographic videos of this nature provide complex information in short “utterances” (zero to three minutes) that researchers use to effectively convey local meaning to other participants in the process. Video utterances can be used to create opportunities for participation in product ideation, recognize key features and identify problems during product testing. With proper scaffolding, the video utterances are an effective means of contextual representation proving to be quick, direct and influential with product development teams. Using video of this kind impacts the product as the local, ethnographic meaning is sustained throughout development.
Verfremdung and Business Development: The Ethnographic Essay as Eye‐opener
Authors: DALSGAARD ANNE LINE
Published: July 2009

This paper discusses the use of essays as tools for communication and reflection in a collaborative research and development process between a philosopher, an anthropologist, and two private companies. Findings from the project “The Meaning of Work Life” will be presented along with a discussion about their relevance for the involved companies. To specify the general anthropological strategy of defamiliarization, the notion of verfremdung1 is used to detail out specific features of the analytical and representational perspective employed. The paper concludes that the meaning of research results cannot be controlled, as they will always be interpreted according to personal or professional agendas, which is why a style of representation that lays bare their status as interpretations is not only appropriate but may even — by way of estrangement ‐ be revealing and innovative. This conclusion is not new to anthropology as such, but within the context of business ethnography (in which more and more anthropologists are engaged) it has a renewed relevance.
The Space Between Mine and Ours: Exploring the Subtle Spaces Between the Private and the Shared in India
Authors: ASOKAN ASHWINI
Published: July 2009

Starting from their interactions within shared spaces and use of shared objects, to large social networks, the Indian society has developed a range of ways to incorporate subtle gestures and systems into their lives that neither forces them to share all their time and space with everyone, nor isolates them completely. This paper explores this idea that privacy is not always mutually exclusive from shared states. In the process, it highlights quality of time and space as a construct of subtle negotiations between the socially structured and personally desired. These subtleties allow Indians to design their lives around extensive grey spaces that exist in between the community and individual. This suggests some new ways for us to think about meaning of privacy, and its impact on how people in countries like India navigate complex social networks, cultural systems, and rigid social hierarchies, very often using technologies like phones and TVs.
Drawing from Negative Space: New Ways of Seeing Across the Client‐Consultant Divide
Authors: CHANG MICHELE FRANCES , LIPSON MATTHEW
Published: July 2009

Focusing on the client‐consultant relationship, well honed, but perhaps overly so, this paper aims to shed light on the conditions that at once streamline and challenge our collaborations. To do so, we borrow a page from the visual arts; namely an experimental method of representation called negative space drawing. In both its aim (to create a picture from a new perspective) and challenge (to shake off the preconceived notions that limit us) drawing from negative space reflects a similar dynamic to our own. By way of a case study commissioned by one author and conducted by the other, we sketch a framework of negative space which examines our respective biases and agendas and our endeavors to resolve them.
The QAME of Trans‐disciplinary Ethnography: Making Visible Disciplinary Theories of Ethnographic Praxis as Boundary Object
Authors: TUNSTALL ELIZABETH (DORI)
Published: July 2009

Framed by the idea that ethnography is a trans‐disciplinary praxis, this paper adopts Alan Barnard's framework of the theory as questions, assumptions, methods, and evidence (QAME) to compare how ethnographic praxis is approached across the domains of anthropology, marketing, and design. The companies Intel, Cheskin, and IDEO serve as exemplars for each domain, respectively. Through a content analysis of academic journals and popular media, the paper explores the discursive meanings of ethnography as a “boundary object” across many domains. The paper concludes with how Barnard's QAME framework can be used to make visible ethnography's multiple meanings so that practitioners can improve interdisciplinary collaborations within organizations and better articulate ethnography's value to business.
Tracing the Arc of Ethnographic Impact: Success and (In)visibility of Our Work and Identities
Authors: FLYNN DONNA K. , LOVEJOY TRACEY
Published: July 2009

This paper explores ways in which ethnographic impact in a large technology corporation is perceived, redefined, and recognized — by both practitioners themselves and corporate stakeholders. The authors trace a history of ethnographic successes and stumbles, and ways they have confronted a strong usability paradigm that has shaped organizational assumptions of impact and value for product research. They then identify ways in which contextual analysis of their own practice in the corporation led to the successful creation of a strategic engagement model for ethnography, resulting in its growing influence. Through critical analysis of the conditions of influence in their own organization, the authors' propose some broader frameworks for ethnographic impact and raise some questions for the EPIC community regarding business value, ethnographic identity, and organizational authority.
Genetically correlated effects of selective breeding for high and low methamphetamine consumption
Authors: Wheeler J. M. , Reed C. , Burkhart‐Kasch S. , Li N. , Cunningham C. L. , Janowsky A. , Franken F. H. , Wiren K. M. , Hashimoto J. G. , Scibelli A. C. , Phillips T. J.
Published: July 2009

Improved prevention and treatment of drug addiction will require deeper understanding of genetic factors contributing to susceptibility to excessive drug use. Intravenous operant self‐administration methods have greatly advanced understanding of behavioral traits related to addiction. However, these methods are not suitable for large‐scale genetic experiments in mice. Selective breeding of mice can aggregate ‘addiction alleles' in a model that has the potential to identify coordinated effects of multiple genes. We produced mouse lines that orally self‐administer high (MAHDR) or low (MALDR) amounts of methamphetamine, representing the first demonstration of selective breeding for self‐administration of any psychostimulant drug. Conditioned place preference and taste aversion results indicate that MAHDR mice are relatively more sensitive to the rewarding effects and less sensitive to the aversive effects of methamphetamine, compared to MALDR mice. These results validate the oral route of self‐administration for investigation of the motivational effects of methamphetamine and provide a viable alternative to intravenous self‐administration procedures. Gene expression results for a subset of genes relevant to addiction‐related processes suggest differential regulation by methamphetamine of apoptosis and immune pathways in the nucleus accumbens of MAHDR and MALDR mice. In each line, methamphetamine reduced an allostatic state by bringing gene expression back toward ‘normal’ levels. Genes differentially expressed in the drug‐naï ve state, including Slc6a4 (serotonin transporter), Htr3a (serotonin receptor 3A), Rela [nuclear factor κB (NFκB)] and Fos (cFos), represent candidates whose expression levels may predict methamphetamine consumption and susceptibility to methamphetamine reward and aversion.
Clustering by neurocognition for fine mapping of the schizophrenia susceptibility loci on chromosome 6p
Authors: Lin S.‐H. , Liu C. ‐M. , Liu Y. ‐L. , Shen‐Jang Fann C. , Hsiao P. ‐C. , Wu J. ‐Y. , Hung S. ‐I. , Chen C. ‐H. , Wu H. ‐M. , Jou Y. ‐S. , Liu S. K. , Hwang T. J. , Hsieh M. H. , Chang C. ‐C. , Yang W. ‐C. , Lin J. ‐J. , Chou F. H. ‐C. , Faraone S. V. , Tsuang M. T. , Hwu H. ‐G. , Chen W. J.
Published: July 2009

Chromosome 6p is one of the most commonly implicated regions in the genome‐wide linkage scans of schizophrenia, whereas further association studies for markers in this region were inconsistent likely due to heterogeneity. This study aimed to identify more homogeneous subgroups of families for fine mapping on regions around markers D6S296 and D6S309 (both in 6p24.3) as well as D6S274 (in 6p22.3) by means of similarity in neurocognitive functioning. A total of 160 families of patients with schizophrenia comprising at least two affected siblings who had data for eight neurocognitive test variables of the continuous performance test (CPT) and the Wisconsin card sorting test (WCST) were subjected to cluster analysis with data visualization using the test scores of both affected siblings. Family clusters derived were then used separately in family‐based association tests for 64 single nucleotide polymorphisms (SNPs) covering the region of 6p24.3 and 6p22.3. Three clusters were derived from the family‐based clustering, with deficit cluster 1 representing deficit on the CPT, deficit cluster 2 representing deficit on both the CPT and the WCST, and a third cluster of nondeficit. After adjustment using false discovery rate for multiple testing, SNP rs13873 and haplotype rs1225934‐rs13873 on BMP6‐TXNDC5 genes were significantly associated with schizophrenia for the deficit cluster 1 but not for the deficit cluster 2 or nondeficit cluster. Our results provide further evidence that the BMP6‐TXNDC5 locus on 6p24.3 may play a role in the selective impairments on sustained attention of schizophrenia.
The Effects of Dehydroepiandrosterone (DHEA)/DHEA-Sulfate (DHEAS) on the Contraction Responses of the Clitoral Cavernous Smooth Muscle from Female Rabbits
Authors: Lee Shin Young , Myung Soon Chul , Lee Moo Yeol , Kim Tae Hyoung , Kim Sae Chul , Kim Kyung Do , Park Soo Hyun , Kim Won Yong
Published: July 2009

Introduction

Dehydroepiandrosterone (DHEA) is a multifunctional steroid that is increasingly available as a supplement aimed at improving libido and well-being in postmenopausal women in the recent times. Together with its sulfate version, DHEA-sulfate (DHEAS), it is the most abundant steroid in humans. The clitoris is an important component of the female sexual response, with its increased vascular response during sexual arousal that results in erection.

Aims

To elucidate the direct effects of DHEA/DHEAS on the vasomotor reactivity of the rabbit clitoral cavernosum.

Methods

Twenty New Zealand white female rabbits weighing approximately 2.5–3 kg were used in the study.

Main Outcome Measures

The contractile response of clitoral cavernous smooth muscle strips in response to phenylephrine (PE; 10−9–10−4 M) were observed in rabbits. Additionally, DHEA/DHEAS effects on phenylephrine-induced contraction and/or acetylcholine-induced relaxation of phenylephrine-induced contraction were measured.

Results

DHEA/DHEAS did not elicit any remarkable response in the resting state. However, both DHEA and DHEAS evoked dose-dependent relaxations of PE-induced contraction. The contractile responses to high potassium were significantly decreased in the DHEA/DHEAS-pretreated strips, compared with the DHEA/DHEAS-nontreated strips. Additionally, contractions by Bay K 8644 (10−7–10−6 M) treatment were also significantly inhibited by DHEA/DHEAS. DHEA-induced relaxation responses were stronger than DHEAS-induced relaxation responses. Various K channel blockers, tetraethylammonium (TEA; 1 mM, 10 mM), 4-aminopyridine (10 µM) and glibenclamide (10 µM) did not affect the DHEA/DHEAS-induced relaxation on muscle strips contracted by PE. Relaxation responses by acetylcholine or sodium nitroprusside (SNP) were not changed after DHEA/DHEAS pretreatment.

Conclusions

DHEA/DHEAS was found to induce a relaxation response in rabbit clitoral cavernosal smooth muscle, and this is thought to be mediated by direct inhibition of a voltage-dependent calcium channel.
Helping a Man with Leprosy: A Case Study
Authors: Guimarães Heloísa C. Q. C. P. , Barros Alba L. B. L. , Bassoli Sidinéia R. B. , Salotti Selma R. A. , Oda Roseli M. , Lunney Margaret
Published: July 2009

PURPOSE.  This case study illustrates nursing diagnoses and interventions for a man with leprosy.

DATA SOURCES.  Data sources were published literature on the disease of leprosy, and the experience and expertise of the authors in working with people with leprosy.

DATA SYNTHESIS.  Data were synthesized using the standardized nursing languages of North American Nursing Diagnosis Association International and the Nursing Interventions Classification. The accuracy of the diagnoses and the appropriateness of the nursing interventions were supported by the positive health outcomes of the patient.

CONCLUSIONS.  Although leprosy has been eradicated in some countries, the risk of new cases is present anywhere that Mycobacterium leprae still exists. The recommended treatment of multibacilar polychemotherapy has lowered the rate of new cases in Brazil.

IMPLICATIONS FOR NURSING PRACTICE.  Nurses need to incorporate evidence‐based practice interventions for leprosy‐based wound care, and nurses should encourage persons with leprosy to maintain regular medical care with multibacilar polychemotherapy.
A Comprehensive Review of Prehospital and In-Hospital Delay Times in Acute Stroke Care
Authors: Evenson K. R. , Foraker R. E. , Morris D. L. , Rosamond W. D.
Published: July 2009

The purpose of this study was to systematically review and summarize prehospital and in-hospital stroke evaluation and treatment delay times. We identified 123 unique peer-reviewed studies published from 1981 to 2007 of prehospital and in-hospital delay time for evaluation and treatment of patients with stroke, transient ischemic attack, or stroke-like symptoms. Based on studies of 65 different population groups, the weighted Poisson regression indicated a 6·0% annual decline ( P<0·001) in hours/year for prehospital delay, defined from symptom onset to emergency department arrival. For in-hospital delay, the weighted Poisson regression models indicated no meaningful changes in delay time from emergency department arrival to emergency department evaluation (3·1%, P=0·49 based on 12 population groups). There was a 10·2% annual decline in hours/year from emergency department arrival to neurology evaluation or notification ( P=0·23 based on 16 population groups) and a 10·7% annual decline in hours/year for delay time from emergency department arrival to initiation of computed tomography ( P=0·11 based on 23 population groups). Only one study reported on times from arrival to computed tomography scan interpretation, two studies on arrival to drug administration, and no studies on arrival to transfer to an in-patient setting, precluding generalizations. Prehospital delay continues to contribute the largest proportion of delay time. The next decade provides opportunities to establish more effective community-based interventions worldwide. It will be crucial to have effective stroke surveillance systems in place to better understand and improve both prehospital and in-hospital delays for acute stroke care.
Solution to the Dilemma of the Migrant Labor Shortage and the Rural Labor Surplus in China
Authors: Chen Guifu , Hamori Shigeyuki
Published: July 2009

Since 2003, China's labor market has been facing two coexisting crises: a rural labor surplus and a severe shortage of migrant labor. Using data from the 2000 China Health and Nutrition Survey questionnaire, which covers 288 villages in 36 counties, this paper attempts to find a solution to this dilemma. Specifically, a multinomial logit model, a Mincer‐type model and a probit model are applied to examine the effect of educational level on the employment choices for rural laborers, and on the wages and the employment status of migrants. Based on the results of our analysis, we propose the implementation of policy aimed at increasing the educational level of rural dwellers, in conjunction with other policies to eliminate all artificial barriers, to facilitate the migration of rural laborers.
Budget Structure and Pollution Control: A Cross‐country Analysis and Implications for China
Authors: Zhang Li , Zheng Xinye
Published: July 2009

In the published literature, the differences in environmental performance across countries are typically explained using the Environmental Kuznets Curve. The Environmental Kuznets Curve states that pollution initially increases with economic growth. Once GDP per capita reaches a certain level, the relationship reverses. In the present paper, we provide an alternative hypothesis, where budget structure plays an important role in explaining the variations in pollution across the world: the lower the business‐related taxes as a share of total tax revenue, the higher the property tax in total tax revenue and the higher the ratio of public health expenditure in total expenditure, then the stronger the incentive of pollution control and the lower the pollution level. Our empirical findings reveal that the budget structure does have an important impact on pollution control. The policy implication of this research is that effective control of environmental pollution requires changes in tax structure and expenditure assignment. This research has important policy implications for China's tax system reform and pollution control efforts.
Influencing the influencers: a theory of strategic diffusion
Authors: Galeotti Andrea , Goyal Sanjeev
Published: July 2009

The growth of the Internet and assorted technologies has made it possible to collect and process detailed information on social networks. This article investigates how firms (and governments) can harness the power of social networks to promote their goals. We show that the optimal use of social networks leads to higher sales and greater profits. However, an increase in the level and dispersion of social interaction can increase or decrease the optimal influence strategy and profits of the player, depending on the content of the interaction. Optimal influence strategies will target individuals with low or high connections, depending on the content of interaction. Finally, the returns to investing in market research on social networks are greater in more unequal networks.
Intermediary ecosystem metabolism as a main driver of methanogenesis in acidic wetland soil
Authors: Drake Harold L. , Horn Marcus A. , Wüst Pia K.
Published: July 2009

Methanogens have a very limited substrate range, and their in situ activities are thus linked to ‘intermediary ecosystem metabolism’, i.e. complex trophic interactions with other microorganisms catalysing essential intermediary processes that ultimately drive methanogenesis. However, information on intermediary ecosystem metabolism and associated biota is fragmented and often conceptualized rather than resolved. The main objective of this review is to evaluate the concept of intermediary ecosystem metabolism in context with recent work aimed at resolving the complex trophic interactions of a methane‐emitting peatland.
The Involution Correspondence in Plane Elastostatics for Regions Bounded by a Circle
Authors: Honein T. , Herrmann G.
Published: July 2009

It is shown that the elastic field induced by prescribed displacements or surface tractions acting on a circular disk (inner region) can be expressed in terms of the elastic field induced by the same quantities acting on the circular boundary (hole) of an infinite plane (outer region), and vice versa. It is shown further that this correspondence is an involution. This novel representation permits one to express the elastic field in a disk with either vanishing displacements or tractions along the boundary in terms of the elastic field of an infinite domain, provided all singularities are in the inner region. Similarly, the elastic field in the outer region can be expressed in terms of the elastic field of the infinite domain, provided all singularities reside in the outer region. The expressions so-derived possess simple algebraic character and are universal in the sense of being independent of the applied loads (singularities) in the two problems.
Behavior of Unanchored Fluid-Filled Tanks Subjected to Ground Excitation
Authors: Natsiavas S. , Babcock C. D.
Published: July 2009

An analysis developed for the response of liquid storage tanks under horizontal base excitation is employed and numerical results are obtained for unanchored tanks. These results are compared and found to be in good agreement with experimental data. Base uplift is shown to cause a dramatic reduction in the effective beam-type stiffness of a tank, which in turn reduces the tank response frequency and changes the developed hydrodynamic loads significantly. Based on these results, an explanation is provided for some great qualitative and quantitative differences in the behavior of a tank, resulting from its base fixity condition alone.
Vibrations of an Inextensible, Air-Inflated, Cylindrical Membrane
Authors: Plaut R. H. , Fagan T. D.
Published: July 2009

Two-dimensional vibrations of a long cylindrical membrane are considered. The membrane is attached to a horizontal base along two generators and is inflated with air. It is assumed that the membrane material is inextensible. The weight of the membrane is included in the analysis. First, the equilibrium shape of the cross-section is determined, and then small vibrations about this configuration are studied. It is found that the vibration frequencies decrease as the membrane weight is increased.
The Dynamics of a Deformable Body Experiencing Large Displacements
Authors: Koppens W. P. , Sauren A. A. H. J. , Veldpaus F. E. , van Campen D. H.
Published: July 2009

A general description of the dynamics of a deformable body experiencing large displacements is presented. These displacements are resolved into displacements due to deformation and displacements due to rigid body motion. The former are approximated with a linear combination of assumed displacement fields. D’Alembert’s principle is used to derive the equations of motion. For this purpose, the rigid body displacements and the displacements due to deformation have to be independent. Commonly employed conditions for achieving this are reviewed. It is shown that some conditions lead to considerably simpler equations of motion and a sparser mass matrix, resulting in CPU time savings when used in a multibody program. This is illustrated with a uniform beam and a crank-slider mechanism.
Remarks on the Static and Dynamic Imperfection-Sensitivity of Nonsymmetric Structures
Authors: Elishakoff Isaac
Published: July 2009

The simple static and dynamic buckling model (the three-hinge rigid-rod system, constrained laterally by a nonlinear spring) originally proposed by Budiansky and Hutchinson, is modified so that the force of the spring includes both quadratic and cubic terms. Expressions are given for the buckling load of the imperfect structure as function of the imperfection. These formulas generalize the classical expressions for the static buckling load (due to Koiter), and for the dynamic buckling load (due to Budiansky and Hutchinson) for symmetric or asymmetric structures, to nonsymmetric ones.
Effect of Transverse Shear and Rotatory Inertia on Large Amplitude Vibration of Anisotropic Skew Plates: Part 1—Theory
Authors: Sathyamoorthy M. , Chia C. Y.
Published: July 2009

A nonlinear vibration theory for anisotropic elastic skew plates is developed with the aid of Hamilton’s principle. The effects of transverse shear deformation and rotatory inertia are included in the analysis. The differential equations formulated here readily reduce to the dynamic von Karman-type equations of skew plates when the shear and rotatory inertia effects are neglected. Solutions to these equations are presented for various boundary conditions in the second part of the paper.
Response of a Roadway Lying on an Elastic Foundation to Random Traffic Loads
Authors: Le Houedec D.
Published: July 2009

This paper analyzes the response of a roadway lying on a Westergaard foundation to the pressures of a load moving on a random profile at a constant velocity. The profile power spectrum is based on experimental recordings done on French roads. From the vibrating axle characteristics, we may deduce the power spectrum of the exciting load. Then, we examine random bending vibrations so as to determine the expected mean square displacements of the roadway. We compare the results obtained for random and harmonic profiles. We notice that with the hard rubber foundation, mean values of deflections are comparable. On the other hand, with the soft rubber foundation, the displacement amplitudes for random excitation are much higher than results deduced for harmonic excitation. Consequently, it appears that with various isolation types, the sine profile is not sufficient to predict the roadway behavior. In fact, the actual behavior depends upon the profile power spectrum and vehicle characteristics.
Creep of 2618 Aluminum Under Step Stress Changes Predicted by a Viscous-Viscoelastic Model
Authors: Lai J. S. , Findley W. N.
Published: July 2009

Nonlinear constitutive equations are developed and used to predict from constant stress data the creep behavior of 2618 Aluminum at 200°C (392°F) for tension or torsion stresses under varying stress history including stepup, stepdown, and reloading stress changes. The strain in the constitutive equation employed includes the following components: linear elastic, time-independent plastic, nonlinear time-dependent recoverable (viscoelastic), nonlinear time-dependent nonrecoverable (viscous) positive, and nonlinear time-dependent nonrecoverable (viscous) negative. The modified superposition principle, derived from the multiple integral representation, and strain-hardening theory were used to represent the recoverable and nonrecoverable components, respectively, of the time-dependent strain in the constitutive equations. Excellent-to-fair agreement was obtained between the experimentally measured data and the predictions based on data from constant-stress tests using the constitutive equations as modified.
Dynamic Plastic Response of Circular Plates With Transverse Shear and Rotatory Inertia
Authors: Jones Norman , Gomes de Oliveira J.
Published: July 2009

The response of a simply supported circular plate made from a rigid perfectly plastic material and subjected to a uniformly distributed impulsive velocity is developed herein. Plastic yielding of the material is controlled by a yield criterion which retains the transverse shear force as well as bending moments and the influence of rotatory inertia is included in the governing equations. Various equations and numerical results are presented which may be used to assess the importance of transverse shear effects and rotatory inertia for this particular problem.
Angled Elliptic Notch Problem Under Biaxial Loading
Authors: Chang K. J. , Wu H.-C.
Published: July 2009

The strain failure criterion proposed by the second author is applied to obtain general solutions for the angled elliptic notch problem subject to uniform biaxial loading. The solutions can be reduced to those for uniaxial tension, uniaxial compression, or pure shear as special cases. The solution for the case of pure shear is compared with experimental data found in literature. It is remarked that the present theory involves material parameters and predicts that fracture behavior is dependent on materials being investigated.
An Energy Method for Certain Second-Order Effects With Application to Torsion of Elastic Bars Under Tension
Authors: Shield R. T.
Published: July 2009

When a mechanical system has a potential energy, it is a simple matter to show that if the generalized force corresponding to a coordinate p is known to first order in p for a range of the other coordinates of the system, then the other generalized forces can be found immediately to second order in p, without requiring a second-order analysis of the system. By this method the second-order change in the axial force when a finitely extended elastic cylinder is twisted is found from the first-order value of the twisting moment. Numerical results for a realistic form of the strain-energy function for an incompressible material suggest that the second-order expression for the axial force is very accurate for a wide range of twist for circular cylinders of rubber-like materials extended 100 percent or more.
Formation of Vortex Street in Laminar Boundary Layer
Authors: Kiya M. , Arie M.
Published: July 2009

Main features of the formation of vortex street from free shear layers emanating from two-dimensional bluff bodies placed in uniform shear flow which is a model of a laminar boundary layer along a solid wall. This problem is concerned with the mechanism governing transition induced by small bluff bodies suspended in a laminar boundary layer. Calculations show that the background vorticity of shear flow promotes the rolling up of the vortex sheet of the same sign whereas it decelerates that of the vortex sheet of the opposite sign. The steady configuration of the conventional Karman vortex street is not possible in shear flow. Theoretical vortex patterns are experimentally examined by a flow-visualization technique.
Finite Thermoelastic Deformation of Sphere With Temperature-Dependent Properties
Authors: Kamiya N.
Published: July 2009

The present paper concerns a finite thermoelastostatic analysis considering temperature-dependent mechanical and thermal properties of material. The Lame´ elastic parameters, thermal expansion coefficient, and thermal conductivity are expressed by linear functions of temperature. Higher-order terms in terms of temperature and strain invariants are introduced into the free energy expression. Lagrange formulation is employed for derivation of the governing field equations. A hollow sphere under a spherically symmetric stationary thermal field is analyzed numerically. The influence of the temperature-dependent variations of the material properties on stress state is investigated and found to be insignificant over a narrow temperature range where the material remains elastic.
A Reinterpretation of the Palmgren-Miner Rule for Fatigue Life Prediction
Authors: Hashin Z.
Published: July 2009

It is shown that the simple Palmgren-Miner linear cumulative damage rule is a special case of a general cumulative damage theory previously established. Predictions of lifetimes for families of multistage loadings according to the Palmgren-Miner rule and the general cumulative damage theory are compared with the aim of arriving at qualitative guidelines for applicability of the Palmgren-Miner rule in cyclic loading programs.
Vibrated Pendulum With a Mass Free to Move Radially
Authors: Schmidt B. A.
Published: July 2009

This work concerns a pendulum made up of a mass and a weightless rod attached to a pivot. The mass is constrained to move rotationally with the rod but is free to move along the rod. Horizontal vibration of the pivot causes an inertia force in the negative radial direction which prevents the mass from sliding off the rod. Stability of an equilibrium solution is determined.
The Null Dynamical Effect, and Some Frequency Spectra, of Resonant Inertial Pressure Waves in a Rapidly Rotating, Right Circular, Sectored Cylinder
Authors: Scott W. E.
Published: July 2009

It is shown that inertial waves in the form of standing asymmetrical pressure waves can exist in an incompressible liquid in a rotating sectored cylinder in a rigid body (e.g., a top or a missile) executing a small amplitude gyroscopic motion about its center of mass. Some of the frequency spectra of these waves are presented along with the result that sectoring the cylinder into any number of equal sectors results in eliminating the destabilizing effect of these waves (i.e., the amplitude growth of the motion of the rigid container) when there is a “Stewartson” resonance between the frequency of one of the inertial modes and the frequency of the nutational component of the motion of the container. Experimental results are in reasonable agreement with the theory.
Stokes Flow in a Driven Sector by Two Different Methods
Authors: Sanders J. , O’Brien V. , Joseph D. D.
Published: July 2009

A biorthogonal series expansion and a numerical finite-difference approximation are applied to the problem of steady Stokes flow in a driven sector of 10° total angle, providing mutual support of the theoretical techniques. For this problem the method of biorthogonal series is faster, cheaper, and more accurate.
Random Response of a Rigid Sphere Embedded in a Viscoelastic Medium and Related Problems
Authors: Beltzer A. I.
Published: July 2009

Random and harmonic responses are considered for a rigid movable sphere embedded in a viscoelastic medium. The solution takes into account the filtering effect of the viscoelastic medium on the traveling random waves. The sphere can be also randomly located with respect to a plane at which the spectral density of incident stochastic waves is prescribed. For a Maxwellian medium with small losses the exact stationary response is derived. The results regarding the nonstationary response of the sphere embedded in a Kelvin-Voight medium are obtained numerically. It is shown that the results obtained are applicable to the prediction of mechanical properties of composite materials, as well as to those of buried structures, when these objects are excited by incompletely known or random disturbances.
The Elastostatic Axisymmetric Problem of a Cracked Sphere Embedded in a Dissimilar Matrix
Authors: Kant R. , Bogy D. B.
Published: July 2009

The axisymmetric elastostatic problem of a cracked sphere embedded in a dissimilar matrix is solved by using the solution for a spherical cavity in an infinite medium together with the axisymmetric solution for a cracked sphere given in the companion paper in this issue of the Journal of Applied Mechanics, Pages 538-544. Numerical results are presented for (a) interface stress for various composites (b) dependence of the stress-intensity factor on the material parameters and ratios of crack to sphere radii, (c) the difference in the elastic strain energy for a cracked and uncracked composite.
Numerical Modeling of Dynamic Crack Propagation in Finite Bodies, by Moving Singular Elements—Part 1: Formulation
Authors: Nishioka T. , Atluri S. N.
Published: July 2009

An efficient numerical (finite-element) method is presented for the dynamic analysis of rapidly propagating cracks in finite bodies, of arbitrary shape, wherein linear-elastic material behavior and two-dimensional conditions prevail. Procedures to embed analytical asymptotic solutions for singularities in stresses/strains near the propagating crack-tip, to account for the spatial movement of these singularities along with the crack-tip, and to directly compute the dynamic stress-intensity factor, are presented. Numerical solutions of several problems and pertinent discussions are presented in Part 2 of this paper.
Asymptotic Evaluation of a Combined Stress-Intensity Factor for a Pressurized Cylindrical Shell Containing a Longitudinal Crack
Authors: Nicholson J. W. , Bradley M. R. , Carrington C. K.
Published: July 2009

Sanders’ path-independent energy-release-rate integral I for a cracked shallow shell is used to compute the asymptotic form of the combined stress-intensity factor for a pressurized elastically isotropic cylindrical shell containing a longitudinal crack. The combined stress-intensity factor is expressible in terms of the conventional stretching and bending stress-intensity factors and is a function of Poisson’s ratio v and a dimensionless crack length λ. When λ is small the shell is nearly flat and when λ is large the shell is very thin. Asymptotic formulas for I when λ is small or large are obtained. A numerical solution for λ = 0(1) is also obtained.
Perturbation Analysis of Buckling of Circular Rings Under Nonuniform Normal Pressures
Authors: Hassan S. D. , El-Ghabaty S. S.
Published: July 2009

Perturbation solutions are found for buckling of thin elastic circular rings under nonuniform pressures. The solution leads to the same results obtained before by numerical methods. Two cases of pressure distribution of the form p = p0(1 + ε cos 2mθ) and p = p0[1 + ε(cos 2θ + v cos 4θ)] are considered. The analysis yields equations to determine the ring curvature at any angle and pressure.
The Rotating Beam Gyroscope
Authors: Fox C. H. J. , Burdess J. S.
Published: July 2009

This paper investigates the dynamics of a novel “multisensor” comprising a two-axis gyroscope and a single-axis linear accelerometer. The theoretical analysis indicates that the gyroscope has two modes of operation, untuned and tuned, offering, respectively, angular rate and angular displacement measurement capability, depending on the damping and mistuning present. In addition to the sensing of two-axis angular motion, the instrument is capable of measuring linear acceleration along a third axis. Experimental tests on a prototype instrument show generally good agreement with the theory giving confidence of the development potential of the instrument.
Experiments on Chaotic Motions of a Forced Nonlinear Oscillator: Strange Attractors
Authors: Moon F. C.
Published: July 2009

The forced vibrations of a buckled beam show nonperiodic, chaotic behavior for forced deterministic excitations. Using magnetic forces to buckle the beam, two and three stable equilibrium positions for the postbuckling state of the beam are found. The deflection of the beam under nonlinear magnetic forces behaves statically as a butterfly catastrophe and dynamically as a strange attractor. The forced nonperiodic vibrations about these multiple equilibrium positions are studied experimentally using Poincare plots in the phase plane. The apparent chaotic motions are shown to possess an intricate but well-defined structure in the Poincare plane for moderate damping. The structure of the strange attractor is unravelled experimentally by looking at different Poincare projections around the toroidal product space of the phase plane and phase angle of the forcing function. An experimental criterion on the forcing amplitude and frequency for strange attractor motions is obtained and compared with the Holmes-Melnikov criterion and a heuristic formula developed by the author.
An Application of the Poincare´ Map to the Stability of Nonlinear Normal Modes
Authors: Month L. A. , Rand R. H.
Published: July 2009

The stability of periodic motions (nonlinear normal modes) in a nonlinear two-degree-of-freedom Hamiltonian system is studied by deriving an approximation for the Poincare´ map via the Birkhoff-Gustavson canonical transofrmation. This method is presented as an alternative to the usual linearized stability analysis based on Floquet theory. An example is given for which the Floquet theory approach fails to predict stability but for which the Poincare´ map approach succeeds.
Parametric Resonance Oscillations of Flexible Slender Cylinders in Harmonically Perturbed Axial Flow—Part 1: Theory
Authors: Paidoussis M. P. , Issid N. T. , Tsui M.
Published: July 2009

This paper studies theoretically the dynamical behavior of a flexible slender cylinder in pulsating axial flow. The dynamics of the system in steady, unperturbed flow are examined first. For various sets of boundary conditions the eigenfrequencies of the system at any given flow velocity are determined, and the critical flow velocities are established, beyond which buckling (divergence) would occur. The behavior of the system in pulsating flow is examined next, establishing the existence of parametric resonances. The effects of the mean flow velocity, boundary conditions, dissipative forces, and virtual (hydrodynamic) mass on the extent of the parametric instability zones are then discussed.
Rationale for a Linear Perturbation Method for the Flow Field Induced by Fluid-Structure Interactions
Authors: Sonin A. A.
Published: July 2009

A formal justification is developed for a method in which hydrodynamic data for a transient in a rigid-wall system (derived, for example, from a small-scale experimental simulation) is used as input in a linear computation for the perturbation flow field due to actual wall flexibility. The method is useful in problems where the basic flow transient is so complex that it can be quantified only empirically, and where the fluid-structure interaction is too complex for the fluid side to be represented by a priori defined equivalent mass.
Funnel Flow in Hoppers
Authors: Nguyen T. V. , Brennen C. E. , Sabersky R. H.
Published: July 2009

Detailed observations of funnel flows of dry granular materials in wedge-shaped hoppers of different geometries are presented. The variations of the flow regime with changes in the height of material in the hopper/vertical bin configuration, the width of the vertical bin, the hopper angle and the hopper opening width were investigated and a number of specific flow regimes identified (mass flow and several forms of funnel flow). In the first part of the paper particular attention is paid to the conditions for transition from one flow regime to another; in particular it is shown that the existence of a funnel depends not only on the hopper angle but is also strongly dependent on the geometry of the hopper/bin system. In the second part of the paper the variations in the shape of the funnel near the exit opening are explored in detail.
Creep and Creep Recovery of 304 Stainless Steel Under Combined Stress With a Representation by a Viscous-Viscoelastic Model
Authors: Cho U. W. , Findley W. N.
Published: July 2009

Creep and creep-recovery data of 304 stainless steel are reported for experiments under constant combined tension and torsion at 593°C (1100°F). The data were represented by a viscous-viscoelastic model in which the strain was resolved into five components—elastic, plastic (time-independent), viscoelastic (time-dependent recoverable), and viscous (time-dependent nonrecoverable) which has separate positive and negative components. The data are well represented by a power function of time for each time-dependent strain. By applying superposition to the creep-recovery data, the recoverable creep strain was separated from the nonrecoverable. The form of stress-dependence associated with a third-order multiple integral representation was employed for each strain component. The time-dependent recoverable and nonrecoverable strains had different nonlinear stress dependence; but, the time-independent plastic strain and time-dependent nonrecoverable strain had similar stress-dependence. A limiting stress below which creep was very small or negligible was found for both recoverable and nonrecoverable components as well as a yield limit. The limit for recoverable creep was substantially less than the limits for nonrecoverable creep and yielding. The results showed that the model and equations used in the analysis described quite well the creep and creep-recovery under the stress states tested.
A Semi-Infinite Elastic Strip Bonded to an Infinite Strip
Authors: Adams G. G.
Published: July 2009

The solution is obtained for the plane strain problem of a semi-infinite elastic strip whose end is bonded to and pressed against an infinite elastic strip. The infinite strip is supported by a pair of symmetrically located, concentrated forces. Using integral transform techniques, the solution is reduced to a set of singular integral equations of the second kind. The order of the singularity is determined and the equations are then solved numerically. The results show the normal and shear stress distributions as well as the stress-intensity factors for a range of support locations corresponding to various width ratios and material combinations.
Stress Analysis of a Penny-Shaped Crack Located Between Two Spherical Cavities in an Infinite Solid
Authors: Hirai H. , Satake M.
Published: July 2009

The problem of a penny-shaped crack located between two spherical cavities in an infinite solid subjected to uniaxial loads is considered. Using transformations between harmonic functions in cylindrical coordinates and those in spherical ones, the problem is reduced to nonhomogeneous linear equations. The obtained equations are solved numerically and the influence of the two spherical cavities upon the stress-intensity factors at the penny-shaped crack tip is shown graphically.