bluuebunny/crossref_metadata_2025 huggingface dataset:
Transit Service, Physical Agglomeration and Productivity in US Metropolitan Areas
Authors: Chatman Daniel G. , Noland Robert B.
Published: August 2013

Public transit improvements could cause more clustered and higher-density employment and enable urban growth, giving rise to agglomeration economies by improving labour market accessibility, increasing information exchange and facilitating industrial specialisation. Using data on US metropolitan areas, this paper traces the links from transit service to central city employment density, urbanised area employment density and population; and from these physical agglomeration measures to average wages and per capita GMP. Significant indirect productivity effects of transit service are found. For example, in the case of central city employment density, estimated wage increases range between $1.5 million and $1.8 billion per metropolitan area yearly for a 10 per cent increase in transit seats or rail service miles per capita. Firms and households likely receive unanticipated agglomeration benefits from transit-induced densification and growth, and current benefit–cost evaluations may therefore underestimate the benefits of improving transit service, particularly in large cities with existing transit networks.
Transfer Student Engagement
Authors: Lester Jaime , Brown Leonard Jeannie , Mathias David
Published: August 2013

Transfer students are a distinct population. Their characteristics lead to a qualitatively different student experience. Drawing on interviews with a cross-sectional sample of transfer students at George Mason University (GMU), this study focused on the ways transfer students perceived their social and academic engagement, on the ways they engaged academically and socially at GMU, and on the ways in which their perceptions of engagement and their actual patterns of engagement affected their sense of belonging at GMU. Most notably, transfer students viewed social engagement in the context of family and community rather than college life. The findings have implications for how campuses support transfer students and question assumptions about some engagement theories.
The Validity and Reliability of the Violence Risk Scale–Youth Version in a Diverse Sample of Violent Young Offenders
Authors: Stockdale Keira C. , Olver Mark E. , Wong Stephen C. P.
Published: August 2013

The Violence Risk Scale–Youth Version (VRS-YV; S. Wong, Lewis, Stockdale, & Gordon, 2004-2011) is a risk assessment and treatment planning tool for youths designed to assess violence risk, identify dynamic risk factors or treatment targets, and evaluate changes in risk from treatment or other change agents. We examined the psychometric properties of the VRS-YV on a diverse sample of 147 young offenders. The tool demonstrated high internal consistency (α = .90) and interrater reliability (intraclass correlation coefficient [ICC] = .90). Exploratory factor analysis (EFA) identified three factors: Interpersonal Aggression, Antisocial Tendencies, and Family Problems. VRS-YV static, dynamic, and total scores significantly predicted violent and general recidivism, including youth and adult outcomes, with moderate to high accuracy (area under the curve [AUC] = .65-.77); however, results varied among ethnic/cultural, gender, and developmental subgroups. The VRS-YV also demonstrated strong convergent validity with two well-established youth forensic assessment tools. Clinical implications of these findings and future research directions are discussed in this article.
From Heroic to Post-Heroic Warfare
Authors: Kober Avi
Published: August 2013

Since the late 1970s Israel has been operating postheroically, with postheroic behavior gradually becoming an integral part of its strategic culture and way of war, and often coming at the expense of mission fulfillment. In the Israeli case, the strongest explanation for such behavior has been the marriage of two factors: Israel's engagement in low-intensity conflicts (LICs), which have not threatened its basic security, let alone its existence, and sophisticated technology, which has played a significant facilitating role in applying postheroic warfare. Sparing the lives of the Israel Defense Forces' (IDF's) own troops and of enemy civilians helped gaining greater domestic and legitimacy, as well as greater sustainability in LICs. On the other hand, living up to postheroic warfare's rules had a price not only in terms of fulfilling the military missions, but also in terms of sensitivity to unexpected, sometimes sudden leaps in casualties and/or collateral damage; the danger of lowering the threshold war; and asymmetry with enemies that do not cooperate with postheroic rules and rather fight heroically. The analysis of the Israeli case covers the LIC events Israel has been engaged in from the 1978 Operation Litani, in which postheroic warfare was detected for the same time, to the more recent 2012 Operation Pillar of Defense.
Estimating the Effect of Nonresponse Bias in a Survey of Hospital Organizations
Authors: Lewis Emily F. , Hardy Maryann , Snaith Beverly
Published: August 2013

Nonresponse bias in survey research can result in misleading or inaccurate findings and assessment of nonresponse bias is advocated to determine response sample representativeness. Four methods of assessing nonresponse bias (analysis of known characteristics of a population, subsampling of nonresponders, wave analysis, and linear extrapolation) were applied to the results of a postal survey of U.K. hospital organizations. The purpose was to establish whether validated methods for assessing nonresponse bias at the individual level can be successfully applied to an organizational level survey. The aim of the initial survey was to investigate trends in the implementation of radiographer abnormality detection schemes, and a response rate of 63.7% (325/510) was achieved. This study identified conflicting trends in the outcomes of analysis of nonresponse bias between the different methods applied and we were unable to validate the continuum of resistance theory as applied to organizational survey data. Further work is required to ensure established nonresponse bias analysis approaches can be successfully applied to organizational survey data. Until then, it is suggested that a combination of methods should be used to enhance the rigor of survey analysis.
Statistical Power in Three-Arm Cluster Randomized Trials
Authors: Liu Xiaofeng Steven
Published: August 2013

This article shows how to compute statistical power for testing the main effect of treatment in three-arm cluster randomized trials. Using orthogonal coding, we derive the exact test statistic of the treatment effect and its non-central distribution. The non-centrality parameter in the omnibus test is found to be related to the non-centrality parameters in the contrast tests. A study of physician and pharmacist comanagement of patients’ blood pressure is used as an example to show the power computation in a three-arm cluster randomized trial.
Children: Their Place in Organization Studies
Authors: Kavanagh Donncha
Published: August 2013

This paper argues that children and childhood constitute a ‘white space’ in organization studies, which should now be explored, mapped and analysed. Rather than being separate, children and organization are deeply implicated in one another, which provides a rich basis for theoretical inquiry. The paper draws on Spivak’s concept of the subaltern and on actor-network theory to articulate how and where organization studies might critically engage with, and find a place for, children and childhood. It frames such an inquiry around six potential research trajectories: epistemological, methodological, ontological, temporal, political and reflexive.
Putting The Body Shop in its Place: A Studio-based Investigation into the New Sites and Sights of Organization as Experience
Authors: Rippin Ann
Published: August 2013

Locating organizations is a difficult task, making it difficult to study them and difficult to represent that study. There is no single phenomenon of organization. We identify them through their buildings, brands, products, employees, customers, marketing materials, legal status and so on, but it is hard to identity a single unified entity. This research note argues that organization lies in our encounters with it, that is, our experience of organization which constitutes its existence. In order for scholars of organization to be able to say anything about these experiences we need a methodology designed to capture experience. The work of John Dewey is useful here with his insistence on art as experience. This note takes Dewey’s work on art and applies it to a particular case example – The Body Shop International – and demonstrates how organization studies can be enhanced through an arts or studio-based approach. Indeed, it argues, along with Dewey, that any civilized community of practice might be expected to produce art, and that the organization studies community should welcome an arts practice as a sign of its own maturity.
Bringing Back the Bank: Local Renewal and Agency through Community Banking
Authors: Cutcher Leanne
Published: August 2013

This paper presents findings from an in-depth case study of a bank that has drawn on an anti-globalization discourse and the idea of the “local in opposition to the global” to create a niche for itself in the highly consolidated Australian retail banking market. The paper explores why, despite the contradiction inherent in its discourse, the bank has been able to garner the funds and volunteer effort of locals to establish and extend its branch network. In exploring what motivated the volunteers involved in the establishment of the local bank the paper shows how seemingly impersonal abstract processes of globalization are embedded in local places and worked out through localized practices of agency. These agentic practices were experienced as being connected, authentic, and in control. Yet as always the paradox of agency came into play and throughout the case study we see how these practices of agency are both enabled and constrained by “being local”. By highlighting processes of globalization at the local level these findings move us beyond overarching and overly “neat narratives of globalization” (Maurer, 2003). So that rather than invitations and invocations to “act locally” being seen as “anti-globalization” they should be understood as embedded processes of globalization.
Intracochlear Electrical Stimulation Suppresses Apoptotic Signaling in Rat Spiral Ganglion Neurons after Deafening in Vivo
Authors: Kopelovich Jonathan C. , Cagaanan Alain P. , Miller Charles A. , Abbas Paul J. , Green Steven H.
Published: August 2013

Objective

To establish the intracellular consequences of electrical stimulation to spiral ganglion neurons after deafferentation. Here we use a rat model to determine the effect of both low and high pulse rate acute electrical stimulation on activation of the proapoptotic transcription factor Jun in deafferented spiral ganglion neurons in vivo.

Study Design

Experimental animal study.

Setting

Hearing research laboratories of the University of Iowa Departments of Biology and Otolaryngology.

Methods

A single electrode was implanted through the round window of kanamycin‐deafened rats at either postnatal day 32 (P32, n = 24) or P60 (n = 22) for 4 hours of stimulation (monopolar, biphasic pulses, amplitude twice electrically evoked auditory brainstem response [eABR] threshold) at either 100 or 5000 Hz. Jun phosphorylation was assayed by immunofluorescence to quantitatively assess the effect of electrical stimulation on proapoptotic signaling.

Results

Jun phosphorylation was reliably suppressed by 100 Hz stimuli in deafened cochleae of P32 but not P60 rats. This effect was not significant in the basal cochlear turns. Stimulation frequency may be consequential: 100 Hz was significantly more effective than was 5 kHz stimulation in suppressing phospho‐Jun.

Conclusions

Suppression of Jun phosphorylation occurs in deafferented spiral ganglion neurons after only 4 hours of electrical stimulation. This finding is consistent with the hypothesis that electrical stimulation can decrease spiral ganglion neuron death after deafferentation.
Computed tomography angiography of coronary artery bypass grafts: robustness in emergency and clinical routine settings
Authors: Heye Tobias , Kauczor Hans-Ulrich , Szabo Gabor , Hosch Waldemar
Published: August 2013

Background

There is a high probability for presence of irregular heart rates and artifacts in patients with previous coronary artery bypass graft (CABG) surgery. Previously reported diagnostic performance of ECG-gated 64-slice dual-source computer tomography angiography (CTA) in this patient group is based on pre-selection for normal heart rate and routine clinical setting.

Purpose

To investigate image quality and diagnostic performance of CTA in patients with previous CABG surgery in various clinical settings.

Material and Methods

Fifty-six non-selected, consecutive patients (110 grafts, 44 arterial, 66 venous) with previous CABG surgery were prospectively examined using a dual-source 64-slice CT (Siemens Definition, Forchheim, Germany) without utilization of CT-related pharmaceutical heart rate control. Patients were stratified according to the clinical setting: planned redo-cardiac surgery; emergency CTA within 30 days after CABG surgery; routine follow-up after CABG surgery. A reference standard was available for 30 patients (53.6%; 67/110 grafts). Image quality, artifacts, and graft patency were independently assessed by two observers.

Results

All CTAs were diagnostic despite the presence of irregular heart rhythm (25% of cases) and artifacts (72.7% of grafts). CTA was accurate in all patient groups in assessing graft patency (97.9% sensitivity; 100% specificity; 98.5% accuracy) but artifacts decreased diagnostic performance for stenosis detection (60% sensitivity; 88.6% specificity; 84.1% accuracy). Arterial grafts exhibited more surgical clip artifacts compared to venous grafts, which predominantly showed motion artifacts. Overall diagnostic quality was rated excellent in 70.9%/56.4%, good in 23.4%/39.1%, and sufficient in 5.5%/4.5% by each observer, respectively. CTA detected acute findings in 10 cases (graft bleeding, graft occlusion, pericardial hematoma, sternal instability with retrosternal abscess formation, pericardial effusion, left ventricle thrombus) in the emergency group; seven cases required surgical revision.

Conclusion

Dual-source CTA is a robust and accurate method for assessment of graft patency and detection of relevant extra-cardiac pathologies in a non-selected patient population after CABG surgery in routine as well as emergency clinical settings. Artifacts caused by irregular heart rhythm or surgical clips do not impair graft patency evaluation but limit stenosis assessment.
US-guided transthoracic biopsy of peripheral lung lesions: pleural contact length influences diagnostic yield
Authors: Jeon Kyung Nyeo , Bae Kyungsoo , Park Mi Jung , Choi Ho Cheol , Shin Hwa Seon , Shin Suyoung , Kim Ho Cheol , Ha Chang Yoon
Published: August 2013

Background

Transthoracic biopsy of peripheral lung lesions under ultrasonography (US) guidance is a useful diagnostic technique. However, factors affecting diagnostic yield of US-guided transthoracic biopsy of peripheral lung lesions are not well established.

Purpose

To determine the factors that influence diagnostic yield of US-guided transthoracic biopsy in peripheral lung lesions.

Material and Methods

A total of 100 consecutive patients underwent US-guided percutaneous cutting biopsy of peripheral lung lesions from October 2007 to March 2009. After seven unconfirmed cases were excluded, 97 procedures in 93 consecutive patients were included in this study. The accuracy of the lung biopsies was assessed by comparing the biopsy results with the final diagnoses. We divided the cases into a correct group (true-positive and true-negative) and an incorrect group (false-positive, false-negative, and non-diagnostic results) and analyzed the differences in the lesions, procedures, and patient variables between the two groups.

Results

According to the final diagnoses, 56 cases (57.7%) were malignant and 41 cases (42.3%) were benign. An overall diagnostic accuracy of 91.8% was obtained. The median size of the lesions was 46.0 mm (interquartile range [IQR], 30.0–69.5 mm), and the median lesion-pleura contact arc length (LPCAL) was 31.0 mm (IQR, 18.0–51.0 mm). Multivariate logistic regression analysis showed that only LPCAL (odds ratio, 1.16; 95% CI, 1.04–1.30) was a significant predictor of a correct diagnosis. When we divided the lesions into those with LPCAL values >30 mm and LPCAL values ≤30 mm, the sensitivity (96.6% vs. 74.1%; P = 0.02) and the accuracy (98% vs. 85.4%; P = 0.03) were significantly higher in the group with larger LPCAL.

Conclusion

In US-guided transthoracic biopsy of peripheral lung lesions, the LPCAL of the lesions is an important factor for a correct diagnosis.
Hepatitis B surface antigen seroclearance in patients with chronic hepatitis B infection: A clinical study
Authors: Ruan Peng , Xu Shao-Yong , Zhou Bo-Ping , Huang Jian , Gong Zuo-Jiong
Published: August 2013

Objective

To investigate the clinical characteristics of hepatitis B surface antigen (HBsAg) seroclearance in patients with chronic hepatitis B virus (HBV) infection.

Methods

Patients with chronic HBV infection who achieved sustained virological response (SVR) within 6 years of ceasing formal antiviral treatment were assessed for HBsAg seroclearance (defined as loss of serum HBsAg on repeated testing for a period of >6 months), using enzyme immunoassays. Phase of HBV infection and liver function (serum alanine aminotransferase [ALT] and aspartate aminotransferase [AST] levels) and HBV DNA levels were also assessed.

Results

In total, 272 patients with chronic HBV and SVR were included; HBsAg seroclearance was achieved in 42 patients and not achieved in 230 patients. Serum HBsAg and ALT levels, ratios of HBsAg to HBV DNA and ratios of AST to ALT were significantly different between patients achieving, and not achieving, HBsAg seroclearance. The area under the receiver operating characteristic (ROC) curve of HBsAg levels for predicting the likelihood of HBsAg seroclearance was 0.85; the cut-off value was 203.86 IU/ml.

Conclusions

These data demonstrate that HBsAg seroclearance was independently associated with host immunity, serum HBsAg level, serum ALT level, serum HBsAg to HBV DNA ratio and timing of drug therapy within the course of chronic HBV infection.
Meta-analysis of probiotics and/or prebiotics for the prevention of eczema
Authors: Dang Dan , Zhou Wenli , Lun Zhi Jun , Mu Xin , Wang Dong Xuan , Wu Hui
Published: August 2013

Objective

The efficacy of probiotics and/or prebiotics for preventing eczema in infants remains unclear. This meta-analysis evaluated published studies on pro/prebiotics for eczema prevention, investigating bacterial strain efficacy and changes to the allergy status of the children involved.

Methods

Randomized, double-blind, placebo-controlled trials were analysed, irrespective of bacterial strains used in the pro/prebiotics. Studies of pregnant women, nursing mothers and infants receiving pro/prebiotics were included. All infant participants were assessed within 2 years of birth. Incidences of eczema and systemic sensitization were measured by weighted relative risk ratios (RRR).

Results

The 14 studies on probiotics had a pooled RRR of 0.69 (95% confidence interval [CI]: 0.62, 0.78). Three studies on prebiotic consumption showed a RRR of 0.80 (95% CI: 0.54, 1.18). One study of mixed pro/prebiotic (synbiotic) strains found a RRR ratio of 0.81 (95% CI: 0.66, 0.99). No consistent sensitization changes were found. Only the combination of nonspore lactobacilli and bifidobacteria reduced the incidence of eczema.

Conclusion

This meta-analysis found that probiotics or synbiotics may reduce the incidence of eczema in infants aged <2 years. Systemic sensitization did not change following probiotic administration.
Stress Distribution Within Rotator Cuff Tendons With a Crescent-Shaped and an L-Shaped Tear
Authors: Sano Hirotaka , Hatta Taku , Yamamoto Nobuyuki , Itoi Eiji
Published: August 2013

Background:

There are 2 representative shapes of full-thickness rotator cuff tears commonly observed: crescent-shaped and L-shaped tears. To date, the exact process of tear propagation in each shape remains unknown.

Purpose:

To determine the stress distribution pattern in rotator cuff tendons with a crescent-shaped tear and an L-shaped tear.

Study Design:

Descriptive laboratory study.

Methods:

The computed tomography (CT) data of a normal cadaveric shoulder from a 69-year-old man were used to develop a 3-dimensional finite element model of the rotator cuff tendons. Three different sizes (1.0-, 2.0-, and 3.0-cm widths) of crescent-shaped and L-shaped tears were created. Tensile load was applied to each cuff tendon that simulated shoulder abduction and external rotation in the hanging-arm position. Elastic analysis was performed, and distribution of the von Mises equivalent stress was calculated. Then, the stress distribution pattern was compared between the 2 tear shapes and among the 3 different tear sizes.

Results:

In the crescent-shaped tear models, stress concentration was seen in both the anterior and the posterior edges of the torn tendon stump. In the L-shaped tear models, stress concentration was seen in the posterior torn tendon edge as well as the bottom of the longitudinal tear. The areas with high stress concentration increased with increasing tear size. At the posterior torn tendon edge, a common site of delamination, the articular half represented a higher equivalent stress than the bursal half in all models. The highest equivalent stress increased with an increase in tear size for both the abduction and the external rotation loads.

Conclusion:

A high stress concentration was seen in both the anterior and the posterior tendon edge in crescent-shaped tears and in both the posterior tendon edge and the bottom of the longitudinal tear in L-shaped tears. Stress concentration inside the tendon increased with increasing tear size.

Clinical relevance:

Crescent-shaped tears may propagate in the anterior and posterior directions, whereas L-shaped tears may propagate in the posterior and medial directions. Tear propagation may accelerate with an increase in tear size.
Fibrous and composite materials for blast protection of structural elements—A state-of-the-art review
Authors: Pichandi Subramani , Rana Sohel , Oliveira Daniel , Fangueiro Raul
Published: August 2013

Contemporary world is facing numerous bomb explosion attacks on public and civil buildings causing huge loss of property and human lives. As a consequence, the society needs more safety and protection for the existing structures against blast loads. Among the various strategies, one effective way to enhance the blast resistance of reinforced concrete and masonry structures is through retrofitting using various types and forms of fibrous and composite materials. This work presents an up to date review of available literature and publications on the fibrous and composite materials utilized for blast protection of structural elements and highlights the lacking areas where further research is required.
The Domestic Politics of Protecting Human Rights in Counter-Terrorism
Authors: Carey Henry Frank
Published: August 2013

Three countries in Eastern Europe, Poland, Lithuania, and Romania, hosted secret detention sites for the benefit of the Central Intelligence Agency’s (CIA’s) interrogation program from about 2002 to 2006. All three countries initially denied with indignation these allegations. In the past five years, Poland moved toward prosecution as a result of a Supreme Court decision ordering declassification of documents, which resulted since 2008 in an ongoing prosecutorial investigation likely to indict the former Interior Minister and possibly others. While Lithuania’s parliament identified plans for a site, it claimed to not know whether it was used, and prosecution was aborted. Romania’s secret prison became the host not only to second-tier, high-value detainees of the CIA, but after Poland shut down its site, to the most dangerous detainees, who were tortured in the basement of the National Security Archives Building in Bucharest. Romania’s three governmental branches continue to deny that it ever collaborated with the CIA or that such a site even existed. This essay analyzes this variation in the domestic responses of these three countries, as well as other CIA collaborations with Bosnia, Kosovo, and Macedonia. It argues that international pressure was a necessary condition for domestic political processes, especially in the legislative and judicial branches supervising executive actions. However, the strength of the latter two branches, along with the type of political class and civil society, will explain the strongest reform process in Poland, the medium-range response in Lithuania, and the nonresponse of denial by Romania.
The Use of Eminent Domain for Economic Development in the Era of Kelo
Authors: Lanza Steven P. , Miceli Thomas J. , Sirmans C. F. , Diop Moussa
Published: August 2013

The Supreme Court decision in Kelo v. New London (2005) authorized the use of eminent domain for economic redevelopment provided that there are sufficient spillover benefits to the public. This article examines the economic basis for this decision and tests the conclusions using cross-state data on “development takings” over the period 1998 to 2002. It also examines the political responses by states to limit such takings in the aftermath of Kelo. The results are consistent with the economic justification for eminent domain as a means of overcoming the holdout problem.
Influence of nanotube dispersion and spinning conditions on nanofibre nanocomposites of polypropylene and multi-walled carbon nanotubes produced through ForcespinningTM
Authors: O’Haire T , Rigout M , Russell SJ , Carr CM
Published: August 2013

Melt centrifugal spinning has been used to successfully produce nanofibres from compounds of polypropylene (PP) and multi-walled carbon nanotubes (MWNTs) at a concentration of 1%. The compounds were prepared either via twin screw compounding or by dissolution in decalin with sonication. Nanofibre production was conducted by centrifugal spinning in a Forcespinner™, a technology capable of producing nanofibres with a high material throughput. Processing via dissolution resulted in a reduction in the size of the MWNT agglomerations in the polymer, which led to a more uniform fibre morphology and a reduced incidence of bead defects as compared to products produced from the melt extrusion compound. The addition of a nonionic surfactant (Triton X-100) to the compound solution aided dispersion of the MWNTs as determined by optical light microscopy of thin cast films and produced fibres with the lowest mean diameter. The mean fibre diameter in the as-spun webs prepared by dissolution of PP in decalin with sonication was found to decrease with increasing spinneret speed; however, a similar trend was not observed for fibres generated from the melt compounded material.
A new penetration equation for ballistic limit analysis
Authors: Haque Bazle Z (Gama) , Gillespie John W
Published: August 2013

A new penetration equation for ballistic limit analysis (BLA) of a projectile–target pair is developed and presented. A critical review of the classic BLA (CBLA) has identified that the CBLA penetration equations do not satisfy the conservation of momentum and energy principles simultaneously and completely. It has also been found that the classic definition of residual velocity of the projectile does not quantify the instantaneous rigid body velocity of the projectile at ballistic limit. A new definition of the projectile relative velocity with respect to the target in contact (and in motion) is defined, and this new definition is used to define the projectile instantaneous velocity at ballistic limit. With this new definition of the projectile instantaneous velocity, the new penetration equation is derived satisfying both the conservation of momentum and energy principles simultaneously. A general functional form of the new penetration equation is used in analyzing experimental data and the results are found to match well with the experiments. The new equation is shown to be able to explain projectile residual velocity at and around ballistic limit, can predict the jump velocity at ballistic limit (if any), and is applicable to experimental ballistic data of a wide range of thin and thick targets. The present work sets the background for further development of theoretical penetration models incorporating material properties and parameters of the projectile–target pair.
The effects of carbon nanoparticles on thermal and dielectric properties of bisphenol A polycarbonate
Authors: Abdelaziz Mohamed
Published: August 2013

A series of composite films consisting of bisphenol A polycarbonate (BAPC) and carbon black (CB) as nanofillers were prepared by solution mixing followed by film casting. The influence of both CB content and temperature on thermal and dielectric properties of BAPC was investigated. X-Ray diffraction patterns show semicrystalline nature of the prepared films. The thermal and dielectric properties were carried out as a function of frequency in the range from 20 Hz to 3 MHz, temperature in the range from 20 to 80°C for concentrations 0, 1, 3, 5, 7, 10, and 15 wt% CB. Differential scanning calorimetric results show a decrease in the glass transition temperature and apparent activation energy at decomposition temperature when the CB content increases. The dielectric measurements show that the dielectric constant ( ε′) and alternating current conductivity increase with CB content and also with the temperature. However, the ε′ and dissipation factor decrease with frequency. The increase in ε′ with temperature is due to the formation of new dipoles or accumulation of charge carriers in a nanoparticle–polymer interface. Parameters relating to thermal and dielectric properties of these composites can be controlled by adjusting the CB nanoparticles content in the BAPC matrix and temperature. It could be concluded that the obtained composites should be desirable candidates for high ε′ materials in embedded capacitor applications.
Stress-accelerated photothermal oxidative aging behavior of polyamide 6
Authors: Zhao Xiaowen , Li Xiaohe , Ye Lin , Li Guangxian
Published: August 2013

The long-term stress-accelerated photothermal oxidative aging behavior of polyamide 6 (PA6) was studied in terms of the creep behavior, mechanical properties, chemical structure, crystallization, and orientation behavior. It was found that the creep deformation of PA6 under stress with ultraviolet (UV) irradiation was lower than that of the sample aging without UV irradiation. Due to stress-induced orientation, the tensile strength of PA6 aging under stress was higher than that of the sample aging without stress. For samples aging with stress, the variation in the content of gel tended to slow down, and the reduced viscosity was lower than that of the sample aging without stress. The oxidation of PA6 can be inhibited by orientation, leading to a relatively low content of carboxylic group; however, stress would accelerate the degradation of PA6, resulting in the strengthening of UV absorption. A decrease in crystallinity of PA6 after aging was observed, which was generated by chain scission in crystalline region and the cross-linking of PA6. Stress would accelerate the degradation of PA6, resulting in further decrease in crystallinity. The orientation factor increased obviously in the case of PA6 aged with stress indicating that a clear orientation of molecules induced by stress formed.
An investigation into the static response of fiber-reinforced open conical shell panels considering various types of orthotropy
Authors: Maleki S , Tahani M
Published: August 2013

In this study, bending of composite open conical shell panels subjected to various distributed mechanical loads with various types of orthotropy is investigated. The stiffness coefficients are assumed to be functions of the meridional and circumferential coordinates in panels, which are produced by various methods for the realistic applications. In the first case of orthotropic open conical shell panels, the orientation of fibers are assumed to be in the meridional and circumferential directions. The stiffness coefficients of this type of fiber-reinforced panel are usually assumed to be constant. It is shown that due to the geometry of the conical surface, thickness of laminate will be changed along the meridional direction. The effect of stiffness variation on the response of panel is considered for the first time. In the case of open conical shell panel, which is fabricated by molding the prepreg layers around a conical-shaped mandrel, angle between fibers and meridional lines and, consequently, stiffness coefficients are assumed to be functions of the circumferential coordinates. In the third type, open conical shell panel can be made by cutting from a filament wound circular conical shell. In this case, thickness and ply orientation are functions of the shell coordinates. In this article, different path definitions for variable stiffness filament wound shells are considered. The inclusion of this geometric complicating effect in static analysis will add considerably to the complication and cost of a solution scheme. This article presents some results to show when these assumptions have a significant effect on the end result. The governing equations are based on the first-order shear deformation theory. The governing equations are discretized at whole domain grid points, and the boundary conditions are implemented exactly at boundary grid points using the generalized differential quadrature method. Application of the generalized differential quadrature to the governing equations, solution domain and boundary conditions leads to a system of algebraic equations. Various combinations of clamped, simply supported and free boundary conditions are implemented. It is found that the present method can accurately analyze fiber-reinforced open conical shell panels with various types of orthotropy.
Static balancer for the neck of a face robot
Authors: Cho Changhyun , Kim Seungjong
Published: August 2013

We propose a 3-degree of freedom gravity compensator for the neck of a robotic face. The neck of the face robot is configured with yaw-pitch-pitch-roll rotations. Since the yaw rotation is made parallel to gravity, only the pitch-pitch-roll rotations are considered for gravity compensation. The 1-degree of freedom gravity compensator is located at the first pitch joint. A 2-degree of freedom gravity compensator equivalent to the existing gravity compensator is proposed and applied to the second pitch and roll rotations. A parallelogram is adopted between the first and second pitch rotations. One end of the 2-degree of freedom gravity compensator is attached at the parallelogram and the other is fixed at the face. Wires are used to realize a zero-length spring for all gravity compensators and all springs are located at the base for compact design. Experimental results for gravity compensation show that gravitational torques were effectively counterbalanced by the proposed 3-degree of freedom gravity compensator.
Seismic analysis and evaluation of several recentering braced frame structures
Authors: Hu Jong Wan
Published: August 2013

After earthquakes, residual inter-story drifts greater than 0.5% in buildings may indicate a complete loss of the structure from an economic point of view. Recently, research efforts have been extended to the utilization of superelastic shape memory alloy materials for the smart control systems that can automatically reduce the plastic deformation of the structure subjected to strong seismic loading. Superelastic shape memory alloys are unique metallic alloys that undergo substantial inelastic deformations and regain their original conditions when applied loads are removed, thus alleviating the problem of permanent deformation. The frame structures make the best use of such shape memory alloy’s recentering capability if the superelastic shape memory alloy segments used to replace the steel segments are installed at the part where large deformation is likely to occur. The primary focus of this study is on the seismic response of special steel concentrically braced frames and buckling-restrained braced frames, utilizing superelastic shape memory alloy braces. In order to examine the comparative residual inter-story drift response of both braced frames, 3- and 6-story buildings were designed in accordance with current code specifications, and then nonlinear time-history analyses for two seismic hazard levels were conducted on 2D analytical frame models. The braced frames with superelastic shape memory alloy bracing systems were also compared to those with conventional steel bracing systems. Overall, analysis results show that the superelastic shape memory alloy bracing systems are more effective in decreasing residual inter-story drifts than the conventional steel bracing systems.
A novel method based on least squares support vector regression combing with strong tracking particle filter for machinery condition prognosis
Authors: Li Chengliang , Wang Zhongsheng , Bu Shuhui , Jiang Hongkai , Liu Zhenbao
Published: August 2013

A reliable prediction method is very important to avoid a catastrophic failure. This paper presents a novel method for machinery condition prognosis, named least squares support vector regression strong tracking particle filter which is based on least squares support vector regression combing with strong tracking particle filter. There are two main contributions in our work: first, the regression function of least squares support vector regression is extended, which constructs a bridge for the application of combining data-driven method with a recursive filter based on extend Kalman filter; second, an extend Kalman filter-based particle filter is studied by introducing a strong tracking filter into a particle filter. The strong tracking filter is used to update particles and produce importance densities which can improve the performance of the particle filter in tracking saltatory states, and finally strong tracking particle filter improves the prediction performance of least squares support vector regression in predicting saltatory states. In the experiment, it can be concluded that the proposed method is better than classical condition predictors in machinery condition prognosis.
Forward displacement analysis of a 3-RPR spherical parallel mechanism
Authors: Li Duanling , Zhang Zhonghai , Li He
Published: August 2013

The forward displacement analysis of spherical parallel mechanisms is a nonlinear problem and has attracted the attention of many researchers. A method is proposed to analyze the forward displacement of a 3-RPR spherical parallel mechanism. Firstly, based on spherical geometry and spherical trigonometry theory, a mathematical model is derived for the forward displacement analysis of the spherical parallel mechanism. After simplifying the mathematical model, the kinematical equations are then solved using the resultant elimination method. Using this method, one can obtain the three variables representing the position and pose of the moving platform directly. Finally, a numerical example is presented and Autodesk Inventor software is used to verify all the real solutions. The method of mathematical modeling, equation simplification, resultant elimination presented in this paper can be extended to solve similar problems effectively.
Change and safety: decision-making from data
Authors: Bearfield George , Holloway Anna , Marsh William
Published: August 2013

The UK rail industry collects and analyses incident data to assess the risks experienced by passengers, the railway workforce and members of the public. The current analysis mainly compares current and historic incident rates and, for each type of incident, looks at the railway as a whole. However, changes to reduce risk are often made locally, at least at first, so a modelling approach is needed that is able to analyse local risk. In this paper we present a form of model that is able to make local risk estimates from incident data, using a case study – boarding and alighting incidents at stations. Using a Bayesian network (BN), we analyse the incident data with expert judgements about causal factors. The BN cannot be directly leant from data because the dataset contains no entries for the overwhelming majority of cases where the railway is used without incident. Instead, the incident data is analysed in the context of a model of the use of the railway, so that the prevalence of the causal factors in normal use can be compared with that in the incident data. The usage model is derived from multiple data sets; the use of a BN allows this to be done with approximations. Finally, we show how the model allows local risk to be estimated and consider the wider applicability of the techniques described.
The influence of wind shear to the performance of high-altitude solar-powered aircraft
Authors: Zhong Gao Xian , Xi Hou Zhong , Zheng Guo , Xia Liu Jian , Qian Chen Xiao
Published: August 2013

There is a greatly persistent wind shear in the upper atmosphere, especially at the altitude of 10–20 km. For the idea of dynamic soaring, the wind shear can be treated as a kind of energy resource for aircraft if the aircraft is flying in a proper manner. Based on the above facts, the influence of wind shear to the performance of high-altitude solar-powered aircraft from a new prospect is systemically studied: The wind shear in the upper atmosphere is treated as a kind of energy resource for aircraft, and to be used to compensate the energy consumed by drag. The results of simulations show that the energy extracted from wind shear can compensate about 30–50% of the energy consumed by drag in climbing and 20–40% in descending for high-altitude aircraft when the strength of wind shear is greater than 0.005 s−1 and smaller than 0.01 s−1. This is a valuable conclusion for the high-altitude aircraft, since the strength of wind shear between 10 km and 20 km has fallen into this interval. By defining the dynamic soaring parameter, it has been found that the dynamic soaring parameter is possibly greater than 1 in the place that great enough strength of wind shear can be found, which implies that it is possible for high-altitude aircraft to perform unpowered flight by dynamic soaring if the wind shear can be unitized properly.
Flight testing of noise abating required navigation performance procedures and steep approaches
Authors: Toebben Helmut H , Mollwitz Vilmar , Bertsch Lothar , Geister Robert M , Korn Bernd , Kügler Dirk
Published: August 2013

To test different types of noise abatement approach procedures the Institute of Flight Guidance and the Institute of Aerodynamics and Flow Technology performed flight tests on 6 September 2010 with a Boeing 737-700. In total, 13 approaches to the research airport in Brunswick, Germany (EDVE) were flown while the approach area of the airport was equipped with six noise measurement microphones. Brunswick airport is equipped with an experimental ground based augmentation system which allows the implementation of 49 instrument landing system (ILS) look-alike precision approach procedures with different approach angles simultaneously.
Persistent genital arousal and restless genitalia: sexual dysfunction or subtype of vulvodynia?
Authors: Markos AR , Dinsmore Wallace
Published: August 2013

We conducted a literature review of patients’ conditions described under persistent genital arousal disorder and restless genital syndrome, vulvodynia and male genital skin pain of unknown aetiology (penoscrotodynia). Our aim is to improve the understanding of the condition, unify nomenclature and promote evidence-based practice. The most prominent symptom in persistent genital arousal disorder and restless genital syndrome is a spontaneous, unwelcomed, intrusive and distressing vulval sensation. There are similarities between the clinical presentation of vulvodynia, penoscrotodynia, persistent genital arousal disorder and restless genital syndrome patients. The aetiology of persistent genital arousal disorder and restless genital syndrome, similar to vulvodynia, could be better explained in terms of neuro-vascular dysfunction, genital peripheral neuropathy and/or dysfunctional micro-vascular arterio-venous shunting. Erythromelalgia lends itself to explain some cases of restless genital syndrome, who have concurrent restless legs syndrome; and therefore draw parallels with the red scrotum syndrome. The published literature supports the concept of classifying restless genital syndrome as a sub-type of vulvodynia rather than sexual dysfunction.
Disseminated tuberculosis after extracorporeal shock-wave lithotripsy in an AIDS patient presenting with urosepsis
Authors: Tourchi Ali , Ebadi Maryam , Hosseinzadeh Alireza , Shabaninia Mahsa
Published: August 2013

Haematogenous dissemination of undiagnosed urinary tuberculosis after performing extracorporeal shock-wave lithotripsy (ESWL) is extremely rare. Herein, we report a 41-year-old male who presented with urosepsis to the emergency room; catheterization was performed and retention resolved. He had a tattoo on his left arm and a five-year history of intravenous drug use. Blood tests indicated anaemia, leukocytosis, elevated CRP and ESR and mild hyponatraemia; haematuria, moderate bacteriuria and 2+ proteinuria on urinanalysis were observed. Chest X-ray revealed lesions suggestive of miliary tuberculosis, which was confirmed by chest CT scan. Brain CT and MRI suggested brain involvement in the setting of tuberculosis. On further investigations, HIV infection and hepatitis C seropositivity were detected and the patient remained in a coma for five days with a Glasgow Coma Scale of 6/15. Finally, the diagnosis of haematogenous dissemination of tuberculosis following lithotripsy was established. Anti-tuberculosis and anti-retroviral therapy were prescribed and monthly follow-up visits were scheduled. In conclusion, in a patient diagnosed with ureterolithiasis, a thorough history and physical examination, with specific attention to HIV and tuberculosis predisposing factors, should be carried out and preoperative screening tests considering the possibility of urinary tuberculosis are required. Finally, if urinary tuberculosis is detected, ESWL must be postponed until after appropriate treatment of tuberculosis.
Mental- and Physical-Health Effects of Acute Exposure to Media Images of the September 11, 2001, Attacks and the Iraq War
Authors: Silver Roxane Cohen , Holman E. Alison , Andersen Judith Pizarro , Poulin Michael , McIntosh Daniel N. , Gil-Rivas Virginia
Published: August 2013

Millions of people witnessed early, repeated television coverage of the September 11 (9/11), 2001, terrorist attacks and were subsequently exposed to graphic media images of the Iraq War. In the present study, we examined psychological- and physical-health impacts of exposure to these collective traumas. A U.S. national sample ( N = 2,189) completed Web-based surveys 1 to 3 weeks after 9/11; a subsample ( n = 1,322) also completed surveys at the initiation of the Iraq War. These surveys measured media exposure and acute stress responses. Posttraumatic stress symptoms related to 9/11 and physician-diagnosed health ailments were assessed annually for 3 years. Early 9/11- and Iraq War–related television exposure and frequency of exposure to war images predicted increased posttraumatic stress symptoms 2 to 3 years after 9/11. Exposure to 4 or more hr daily of early 9/11-related television and cumulative acute stress predicted increased incidence of health ailments 2 to 3 years later. These findings suggest that exposure to graphic media images may result in physical and psychological effects previously assumed to require direct trauma exposure.