bluuebunny/crossref_metadata_2025 huggingface dataset:
Sleep Complaints as Risk Factor for Suicidal Behavior in Severely Depressed Children and Adolescents
Authors: Lopes Maria‐Cecilia , Boronat Alexandre C. , Wang Yuan‐Pang , Fu‐I Lee
Published: August 2016

Objectives

To investigate the association between sleep complaints and suicidal behaviors among severely depressed children and adolescents.

Methods

The sample was 214 youths (56.1% males, mean age 12.5 years) with diagnosis of DSM‐IV major depressive disorder consecutively recruited from a university‐based outpatient clinic specialized in mood disorders. The structured interview for children and adolescents was applied to participants. The Children's Depression Rating Scale—revised version—scored the severity of depression, and the Children's Global Assessment Scale assessed the global functioning. Subgroups of patients were compared for psychopathological association by means of logistic regression, in accordance with presence and absence of sleep complaints and suicidality.

Results

The frequency of sleep complaints and suicidal behaviors was, respectively, 66.4% and 52.3%, and both symptoms were observed in 37.9% of patients. Initial insomnia was the most frequent manifestation (58%), followed by night awakening (36%), daytime sleepiness (31%), and early awakening (29.9%). Significant association between sleep disturbance and suicidal behavior was found (odds ratio range of 2.3–10.8).

Conclusion

Sleep disturbances are potential warning manifestations of suicidal behaviors in depressed youth. Possibly, the severity of the active affective episode likely underlies in both sleep complaints and suicidal behaviors among depressed underage patients.
Magnetic resonance based texture parameters as potential imaging biomarkers for predicting long‐term survival in locally advanced rectal cancer treated by chemoradiotherapy
Authors: Jalil O. , Afaq A. , Ganeshan B. , Patel U. B. , Boone D. , Endozo R. , Groves A. , Sizer B. , Arulampalam T.
Published: August 2016

Aim

The study aimed to investigate whether textural features of rectal cancer on MRI can predict long‐term survival in patients treated with long‐course chemoradiotherapy.

Method

Textural analysis (TA) using a filtration−histogram technique of T2‐weighted pre‐ and 6‐week post‐chemoradiotherapy MRI was undertaken using TexRAD, a proprietary software algorithm. Regions of interest enclosing the largest cross‐sectional area of the tumour were manually delineated on the axial images and the filtration step extracted features at different anatomical scales (fine, medium and coarse) followed by quantification of statistical features [mean intensity, standard deviation, entropy, skewness, kurtosis and mean of positive pixels (MPP)] using histogram analysis. Cox multiple regression analysis determined which univariate features including textural, radiological and histological independently predicted overall survival (OS), disease‐free survival (DFS) and recurrence‐free survival (RFS).

Results

MPP [fine texture, hazard ratio (HR) 6.9, 95% CI: 2.43–19.55, P < 0.001], mean (medium texture, HR 5.6, 95% CI: 1.4–21.7, P = 0.007) and extramural venous invasion (EMVI) on MRI (HR 2.96, 95% CI: 1.04–8.37, P = 0.041) independently predicted OS while mean (medium texture, HR 4.53, 95% CI: 1.58–12.94, P = 0.003), MPP (fine texture, HR 3.36, 95% CI: 1.36–8.31, P = 0.008) and threatened circumferential resection margin (CRM) on MRI (HR 3.1, 95% CI: 1.01–9.46, P = 0.046) predicted DFS. For OS, EMVI on MRI (HR 4.23, 95% CI: 1.41–12.69, P = 0.01) and for DFS kurtosis (medium texture, HR 3.97, 95% CI: 1.44–10.94, P = 0.007) and CRM involvement on MRI (HR 3.36, 95% CI: 1.21–9.32, P = 0.02) were the independent post‐treatment factors. Only TA independently predicted RFS on pre‐ or post‐treatment analyses.

Conclusion

MR based TA of rectal cancers can predict outcome before undergoing surgery and could potentially select patients for individualized therapy.
Molecular mechanisms of water table lowering and nitrogen deposition in affecting greenhouse gas emissions from a Tibetan alpine wetland
Authors: Wang Hao , Yu Lingfei , Zhang Zhenhua , Liu Wei , Chen Litong , Cao Guangmin , Yue Haowei , Zhou Jizhong , Yang Yunfeng , Tang Yanhong , He Jin‐Sheng
Published: August 2016

Rapid climate change and intensified human activities have resulted in water table lowering (WTL) and enhanced nitrogen (N) deposition in Tibetan alpine wetlands. These changes may alter the magnitude and direction of greenhouse gas (GHG) emissions, affecting the climate impact of these fragile ecosystems. We conducted a mesocosm experiment combined with a metagenomics approach (GeoChip 5.0) to elucidate the effects of WTL (−20 cm relative to control) and N deposition (30 kg N ha−1 yr−1) on carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes as well as the underlying mechanisms. Our results showed that WTL reduced CH4 emissions by 57.4% averaged over three growing seasons compared with no‐WTL plots, but had no significant effect on net CO2 uptake or N2O flux. N deposition increased net CO2 uptake by 25.2% in comparison with no‐N deposition plots and turned the mesocosms from N2O sinks to N2O sources, but had little influence on CH4 emissions. The interactions between WTL and N deposition were not detected in all GHG emissions. As a result, WTL and N deposition both reduced the global warming potential (GWP) of growing season GHG budgets on a 100‐year time horizon, but via different mechanisms. WTL reduced GWP from 337.3 to −480.1 g CO2‐eq m−2 mostly because of decreased CH4 emissions, while N deposition reduced GWP from 21.0 to −163.8 g CO2‐eq m−2, mainly owing to increased net CO2 uptake. GeoChip analysis revealed that decreased CH4 production potential, rather than increased CH4 oxidation potential, may lead to the reduction in net CH4 emissions, and decreased nitrification potential and increased denitrification potential affected N2O fluxes under WTL conditions. Our study highlights the importance of microbial mechanisms in regulating ecosystem‐scale GHG responses to environmental changes.
Supporting public involvement in interview and other panels: a systematic review
Authors: Baxter Susan , Clowes Mark , Muir Delia , Baird Wendy , Broadway‐Parkinson Andrea , Bennett Carole
Published: August 2016

Background

Members of the public are increasingly being invited to become members of a variety of different panels and boards.

Objective

This study aimed to systematically search the literature to identify studies relating to support or training provided to members of the public who are asked to be members of an interview panel.

Search strategy

A systematic search for published and unpublished studies was carried out from June to September 2015. The search methods included electronic database searching, reference list screening, citation searching and scrutinizing online sources.

Inclusion criteria

We included studies of any design including published and unpublished documents which outlined preparation or guidance relating to public participants who were members of interview panels or representatives on other types of panels or committees.

Data synthesis

Results were synthesised via narrative methods.

Main results

Thirty‐six documents were included in the review. Scrutiny of this literature highlighted ten areas which require consideration when including members of the public on interview panels: financial resources; clarity of role; role in the interview process; role in evaluation; training; orientation/induction; information needs; terminology; support; and other public representative needs such as timing, accessibility and support with information technology.

Discussion and conclusions

The results of the review emphasize a range of elements that need to be fully considered when planning the involvement of public participants on interview panels. It highlights potential issues relating to the degree of involvement of public representatives in evaluating/grading decisions and the need for preparation and on‐going support.
Ischaemic stroke in HIV‐infected patients: a case–control study
Authors: Silva‐Pinto A , Costa A , Serrão R , Sarmento A , Abreu P
Published: August 2016

Objectives

The aim of the study was to provide insights into the contributions of HIV infection stage, antiretroviral therapy (ART) and vascular risk factors to the occurrence of ischaemic stroke in HIV‐infected patients.

Methods

We performed a case–control study of HIV‐infected patients followed in our clinic. We compared patients hospitalized between January 2006 and June 2014 with an ischaemic stroke or transient ischaemic attack to age‐ and gender‐matched controls without stroke.

Results

Of 2146 patients followed in our clinic, we included 23 cases (20 men and three women; mean age 51.3 years) and 23 controls. Eighty‐three per cent of cases had had a stroke and 17% a transient ischaemic attack. According to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification, small‐vessel occlusion was the most frequent aetiology, followed by large‐artery atherosclerosis and cardioembolism. Compared with controls, stroke was statistically significantly associated with diabetes, smoking and low concentrations of high‐density lipoprotein (HDL) cholesterol. Illegal drug use, a low CD4 count and a high viral load were also associated with ischaemic cerebral events. There were no statistically significant differences between cases and controls in Centers for Disease Control and Prevention (CDC) HIV stage, CD4 count nadir and HIV infection time‐to‐event. No statistically significant differences were found concerning ART or treatment compliance.

Conclusions

In our single centre study, we found associations of illegal drug use, HIV replication and some traditional vascular risk factors with the occurrence of ischaemic cerebral events. The paradigm of the care of HIV‐infected patients is changing. Concomitant diseases in the ageing patient with HIV infection, including cerebrovascular disease, must also be addressed in view of their impacts on morbidity and mortality. Apart from controlling the HIV infection and immunosuppression with ART, vascular risk factors must also be addressed.
Hypertension in Russia: Changes Observed After 4 Years of a Comprehensive Health System Improvement Program in the Yaroslavl Region
Authors: Mozheyko Maria , Eregin Sergey , Danilenko Natalia , Vigdorchik Alexey , Tobe Sheldon W. , Campbell Norman , McLean Donna , Baskakova Zhanna , Klimovskaia Ilnaz , Ramanathan Krishnan , Hughes David
Published: August 2016

Rates of cardiovascular mortality and morbidity in Russia have been among the highest in Europe. A comprehensive health system improvement program targeting better diagnosis and control of hypertension was undertaken in the Yaroslavl Region of Russia. This initiative was a joint program between clinicians, the Department of Health and Pharmacy of the Yaroslavl Region, and Novartis Pharma LLC. From 2011 to 2014, the blood pressure control rate improved substantially (94% relative improvement), the percentage of patients with a systolic blood pressure ≥180 mm Hg decreased (from 10% to 5%), and there was a reduction in stroke incidence rate from 4.6 to 3.7 per 1000 population. During this same period, significant changes were made to the way hypertension was diagnosed and treated across all regional government polyclinics, and the use of antihypertensive therapies increased.
Pre‐restorative crown lengthening surgery outcomes: a systematic review
Authors: Pilalas Ioannis , Tsalikis Lazaros , Tatakis Dimitris N.
Published: August 2016

Background

Pre‐restorative crown lengthening surgery (CLS) is a common periodontal procedure, for which systematic reviews are lacking. This systematic review aimed to assess outcomes of CLS performed for restorative reasons.

Methods

Databases (MEDLINE, Scopus, OpenGrey) were searched up to January 2016 for clinical/animal trials on CLS for restorative reasons with ≥6‐month follow‐up. Primary outcomes investigated were: free gingival margin position, probing depth, clinical attachment level, and plaque/inflammation indices.

Results

Four non‐randomized and one randomized controlled clinical trial and one controlled animal trial were included. Heterogeneity and high risk of bias were identified. CLS resulted in increased crown length (6‐month average: 1.4–3.3 mm). Between immediate postsurgery and follow‐up, gingival margin may rebound, largely during the first three postoperative months. Technical (flap positioning, osseous resection, root preparation) and anatomical (periodontal biotype) factors influence outcomes. The literature lacks studies on tooth mobility, crown–root ratio, patient‐ and referring dentist‐reported outcomes, surgical technique comparisons, and restorative treatment timing.

Conclusions

Within the available data limitations, it is concluded that CLS results in increased crown length and possible gingival margin rebound. Technical aspects (primarily) and anatomical factors (secondarily) influence outcomes. Future research is needed to fill significant voids in our knowledge on several procedural aspects.
Prenatal unhealthy diet, insulin‐like growth factor 2 gene (IGF2) methylation, and attention deficit hyperactivity disorder symptoms in youth with early‐onset conduct problems
Authors: Rijlaarsdam Jolien , Cecil Charlotte A.M. , Walton Esther , Mesirow Maurissa S.C. , Relton Caroline L. , Gaunt Tom R. , McArdle Wendy , Barker Edward D.
Published: August 2016

Background

Conduct problems (CP) and attention deficit hyperactivity disorder (ADHD) are often comorbid and have each been linked to ‘unhealthy diet’. Early‐life diet also associates with DNA methylation of the insulin‐like growth factor 2 gene (IGF2), involved in fetal and neural development. We investigated the degree to which prenatal high‐fat and ‐sugar diet might relate to ADHD symptoms via IGF2 DNA methylation for early‐onset persistent (EOP) versus low CP youth.

Methods

Participants were 164 youth with EOP (n = 83) versus low (n = 81) CP drawn from the Avon Longitudinal Study of Parents and Children. We assessed if the interrelationships between high‐fat and ‐sugar diet (prenatal, postnatal), IGF2 methylation (birth and age 7, collected from blood), and ADHD symptoms (age 7–13) differed for EOP versus low CP youth.

Results

Prenatal ‘unhealthy diet’ was positively associated with IGF2 methylation at birth for both the EOP and low CP youth. For EOP only: (a) higher IGF2 methylation predicted ADHD symptoms; and (b) prenatal ‘unhealthy diet’ was associated with higher ADHD symptoms indirectly via higher IGF2 methylation.

Conclusions

Preventing ‘unhealthy diet’ in pregnancy might reduce the risk of ADHD symptoms in EOP youth via lower offspring IGF2 methylation.
Editorial: Bayesian benefits for child psychology and psychiatry researchers
Authors: Oldehinkel Albertine J.
Published: August 2016

For many scientists, performing statistical tests has become an almost automated routine. However, p‐values are frequently used and interpreted incorrectly; and even when used appropriately, p‐values tend to provide answers that do not match researchers' questions and hypotheses well. Bayesian statistics present an elegant and often more suitable alternative. The Bayesian approach has rarely been applied in child psychology and psychiatry research so far, but the development of user‐friendly software packages and tutorials has placed it well within reach now. Because Bayesian analyses require a more refined definition of hypothesized probabilities of possible outcomes than the classical approach, going Bayesian may offer the additional benefit of sparkling the development and refinement of theoretical models in our field.
Risk factors for incident delirium in an acute general medical setting: a retrospective case–control study
Authors: Tomlinson Emily Jane , Phillips Nicole M , Mohebbi Mohammadreza , Hutchinson Alison M
Published: August 2016

Aims and objectives

To determine predisposing and precipitating risk factors for incident delirium in medical patients during an acute hospital admission.

Background

Incident delirium is the most common complication of hospital admission for older patients. Up to 30% of hospitalised medical patients experience incident delirium. Determining risk factors for delirium is important for identifying patients who are most susceptible to incident delirium.

Design

Retrospective case–control study with two controls per case.

Methods

An audit tool was used to review medical records of patients admitted to acute medical units for data regarding potential risk factors for delirium. Data were collected between August 2013 and March 2014 at three hospital sites of a healthcare organisation in Melbourne, Australia. Cases were 161 patients admitted to an acute medical ward and diagnosed with incident delirium between 1 January 2012 and 31 December 2013. Controls were 321 patients sampled from the acute medical population admitted within the same time range, stratified for admission location and who did not develop incident delirium during hospitalisation.

Results

Identified using logistic regression modelling, predisposing risk factors for incident delirium were dementia, cognitive impairment, functional impairment, previous delirium and fracture on admission. Precipitating risk factors for incident delirium were use of an indwelling catheter, adding more than three medications during admission and having an abnormal sodium level during admission.

Conclusions

Multiple risk factors for incident delirium exist; patients with a history of delirium, dementia and cognitive impairment are at greatest risk of developing delirium during hospitalisation.

Relevance to clinical practice

Nurses and other healthcare professionals should be aware of patients who have one or more risk factors for incident delirium. Knowledge of risk factors for delirium has the potential to increase the recognition and understanding of patients who are vulnerable to delirium. Early recognition and prevention of delirium can contribute to improved patients safety and reduction in harm.
Back pain: A puzzle in children
Authors: Nahle Imad S , Hamam Mohamed S , Masrouha Karim Z , Afeiche Nadim E , Abdelnoor Johnny
Published: August 2016

Back pain in children is underdiagnosed and increases incidence in adolescence. A systematic approach can diagnose the most common causes: trauma, structural deformities, inflammatory diseases, infection and malignancy.
Histomorphometric results of different grafting materials and effect of healing time on bone maturation after sinus floor augmentation: a systematic review and meta‐analysis
Authors: Danesh‐Sani S. A. , Engebretson S. P. , Janal M. N.
Published: August 2016

The aim of this systematic review was to evaluate histomorphometric variables, the amount of new bone (NB), residual graft (RG) particles and soft tissue (ST), related to various grafting materials and assess the effect of graft healing time on different histomorphometric outcomes. Studies that were published before October 2015 were electronically and manually searched in three databases. We included human studies that reported the amount of NB, RG and ST in the biopsies taken from the grafted sinuses. Based on the applied grafting materials, extracted data were categorized into different groups. Furthermore, extracted data were classified into three groups based on healing time: (i) ≤ 4.5 mo; (ii) 4.5–9 mo; and (iii) ≥ 9–13.5 mo. The search provided 791 titles. Full text analysis was performed for 258 articles resulting in 136 studies that met the inclusion criteria. Autogenous bone (AB) resulted in the highest amount of NB and lowest amount of RG compared to other grafting materials. Based on this meta‐analysis, a significant difference was noticed in the amount of NB formation in grafts with a healing time of > 4.5 mo when compared to the grafts with less healing time. However, when comparing biopsies taken at 4.5–9 mo of healing (average = 6.22 mo) to the ones taken at ≥ 9–13.5 mo (average = 10.36 mo), no significant difference was noticed in the amount of NB formation of various grafts except allografts that resulted in a significantly higher percentage of NB at 9.5 mo of healing. Based on histomorphometric analysis, AB results in the highest amount of NB formation in comparison to the other grafting materials. Bone substitute materials (allografts, alloplastic materials and xenografts) seem to be good alternatives to autogenous bone and can be considered as grafting materials to avoid disadvantages related to AB, including morbidity rate, limited availability and high volumetric change. Combining AB with alloplastic materials and xenografts brings no significant advantages regarding NB formation.
The Dark Side of the Crisis: Disparities in per Capita income (2000–12) and the Urban‐Rural Gradient in Greece
Authors: Salvati Luca
Published: August 2016

The present study investigates changes (2000–12) in the spatial distribution of per capita income in Greece assessing how economic expansion and recession shape regional disparities in a traditionally‐divided country. Descriptive statistics, multivariate techniques and spatial analysis have been carried out to identify clusters of Greek regions with an homogeneous development path. Results outline how the gap between wealthy and disadvantaged regions consolidated with economic expansion (2000–07) strengthening the centrality of medium‐size urban areas, industrial and tourism‐specialised districts. Recession (2008–12) has widened the gap between Athens and the rest of Greece, while mitigating the disparities in per capita income between rich and poor regions. This evidence seem to contrast with literature indicating how dynamic regions came to be less exposed to recession than economically‐disadvantaged regions. The 2008–09 crisis stimulates a rethinking of the geography of socio‐economic disparities in highly‐divided countries, pointing out how expansion and recession differently impact the spatial distribution of wealth.
Becoming big things: building events and the architectural geographies of incarceration in England and Wales
Authors: Moran Dominique , Turner Jennifer , Jewkes Yvonne
Published: August 2016

This paper advances geographies of architecture beyond frequently studied ‘signature’ buildings by drawing attention to non‐iconic, non‐utopian, banal counterpoints – in this case, new prisons. It argues that by attending to ‘signature’ buildings, architectural geographies have overlooked the critical and underexplored circumstances and contingencies of more quotidian constructions, neglecting the mundane processes of procurement, commissioning, tendering, project management and bureaucratisation – here termed ‘architectural assembly’. Advancing scholarship in carceral geography by considering the processes and assemblages that shape (what will become) carceral spaces, it focuses on what happens before a building takes physical form. The paper draws on a major RCUK‐funded study of prison architecture to move architectural geographies more meaningfully towards a consideration of the bureaucratisation of architectural practice, as underexplored aspects of building ‘events’. It calls for geographers to pay greater attention to the banal geographies of architectural assembly, and to the banalities of production more widely.
Modular Microfluidic Filters Based on Transparent Membranes
Authors: Archibong E. , Tuazon H. , Wang H. , Winskas J. , Pyayt A. L.
Published: August 2016

We propose a new approach to the modular packaging of microfluidic components, in which different functional components are not only fabricated separately but are also designed to be individually removable for the purposes of replacement or subsequent analysis. In this paper, we demonstrate one such component: a stand-alone microfluidic filter that can be custom-fabricated and then connected, disconnected, and replaced on a microfluidic chip as needed. This filter is also designed such that particles captured on the filter can be further analyzed or processed directly on the filter itself—for example, for microscopic examination or cell culturing. The filter is a thin (1 μm) transparent silicon nitride membrane that can be designed and fabricated according to specifications for different applications. This material is suitable for microscale fabrication; filtration of a variety of solutions, including biological samples; and subsequent particle imaging and processing. The porous nature of the thin filter allows for particle separation under relatively low pressures, thus protecting the particles from rupture or membrane damage. We describe two methods for integrating the filter apparatus onto a microfluidic chip such that it can be inserted, removed, and replaced. To demonstrate the utility of this approach, we fabricated custom-designed silicon-based filters, incorporated them onto microfluidic systems then filtered microparticles and live cells from test solutions, and finally removed the filters to image the microparticles and culture the cells directly on the filter membranes.
A Fast Algorithm for Contact Dynamics of Multibody Systems Using the Box Friction Model
Authors: Gholami Farnood , Nasri Mostafa , Kövecses József , Teichmann Marek
Published: August 2016

One of the major challenges in dynamics of multibody systems is to handle redundant constraints appropriately. The box friction model is one of the existing approaches to formulate the contact and friction phenomenon as a mixed linear complementarity problem (MLCP). In this setting, the contact redundancy can be handled by relaxing the constraints, but such a technique might suffer from certain drawbacks, specially in the case of large number of redundant constraints. Most of the common pivoting algorithms used to solve the resulting mixed complementarity problem might not converge when the relaxation terms are chosen as small as they should be. To overcome the aforementioned shortcoming, we propose a novel approach which takes advantage of the sparse structure of the formulated MLCP. This novel approach reduces the sensitivity of the solution of the problem to the relaxation terms and decreases the number of required pivots to obtain the solution, leading to shorter computational times. Furthermore, as a result of the proposed approach, much smaller relaxation terms can be used while the solution algorithms converge.
Targeted Energy Transfers for Suppressing Regenerative Machine Tool Vibrations
Authors: Nankali Amir , Lee Young S. , Kalmár-Nagy Tamás
Published: August 2016

We study the dynamics of targeted energy transfers in suppressing chatter instability in a single-degree-of-freedom (SDOF) machine tool system. The nonlinear regenerative (time-delayed) cutting force is a main source of machine tool vibrations (chatter). We introduce an ungrounded nonlinear energy sink (NES) coupled to the tool, by which energy transfers from the tool to the NES and efficient dissipation can be realized during chatter. Studying variations of a transition curve with respect to the NES parameters, we analytically show that the location of the Hopf bifurcation point is influenced only by the NES mass and damping coefficient. We demonstrate that application of a well-designed NES renders the subcritical limit cycle oscillations (LCOs) into supercritical ones, followed by Neimark–Sacker and saddle-node bifurcations, which help to increase the stability margin in machining. Numerical and asymptotic bifurcation analyses are performed and three suppression mechanisms are identified. The asymptotic stability analysis is performed to study the domains of attraction for these suppression mechanisms which exhibit good agreement with the bifurcations sets obtained from the numerical continuation methods. The results will help to design nonlinear energy sinks for passive control of regenerative instabilities in machining.
Lie Group Forward Dynamics of Fixed-Wing Aircraft With Singularity-Free Attitude Reconstruction on SO(3)
Authors: Terze Zdravko , Zlatar Dario , Vrdoljak Milan , Pandža Viktor
Published: August 2016

This paper proposes an approach to formulation and integration of the governing equations for aircraft flight simulation that is based on a Lie group setting, and leads to a nonsingular coordinate-free numerical integration. Dynamical model of an aircraft is formulated in Lie group state space form and integrated by ordinary-differential-equation (ODE)-on-Lie groups Munthe-Kaas (MK) type of integrator. By following such an approach, it is assured that kinematic singularities, which are unavoidable if a three-angles-based rotation parameterization is applied for the whole 3D rotation domain, do not occur in the proposed noncoordinate formulation form. Moreover, in contrast to the quaternion rotation parameterization that imposes additional algebraic constraint and leads to integration of differential-algebraic equations (DAEs) (with necessary algebraic-equation-violation stabilization step), the proposed formulation leads to a nonredundant ODE integration in minimal form. To this end, this approach combines benefits of both traditional approaches to aircraft simulation (i.e., three angles parameterization and quaternions), while at the same time it avoids related drawbacks of the classical models. Besides solving kinematic singularity problem without introducing DAEs, the proposed formulation also exhibits numerical advantages in terms of better accuracy when longer integration steps are applied during simulation and when aircraft motion pattern comprises steady rotational component of its 3D motion. This is due to the fact that a Lie group setting and applied MK integrator determine vehicle orientation on the basis of integration of local (tangent, nonlinear) kinematical differential equations (KDEs) that model process of 3D rotations (i.e., vehicle attitude reconstruction on nonlinear manifold SO(3)) more accurately than “global” KDEs of the classical formulations (that are linear in differential equations part in the case of standard quaternion models).
Design and Characterization of a Continuous Rotary Minimotor Based on Shape-Memory Wires and Overrunning Clutches1
Authors: Mammano Giovanni Scirè , Dragoni Eugenio
Published: August 2016

An attractive but little explored field of application of the shape-memory technology is the area of rotary actuators, in particular for generating endless motion. This paper presents a miniature rotary motor based on shape-memory alloy (SMA) wires and overrunning clutches, which produces high output torque and unlimited rotation. The concept features an SMA wire tightly wound around a low-friction cylindrical drum to convert wire strains into large rotations within a compact package. The seesaw motion of the drum ensuing from repeated contraction–elongation cycles of the wire is converted into unidirectional motion of the output shaft by an overrunning clutch fitted between drum and shaft. Following a design process developed in a former paper, a six-stage prototype with size envelope of 48 × 22 × 30 mm is built and tested. Diverse supply strategies are implemented to optimize either the output torque or the speed regularity of the motor with the following results: maximum torque = 20 Nmm; specific torque = 6.31 × 10−4 Nmm/mm3; rotation per module = 15 deg/cycle; and free continuous speed = 4.4 rpm.
Analytical Assessment of the Remaining Strength of Corroded Pipelines and Comparison With Experimental Criteria
Authors: Cunha Sérgio B. , Netto Theodoro A.
Published: August 2016

Recently published analytical solutions for the remaining strength of a pipeline with narrow axial and axisymmetric volumetric flaws are described in this paper, and their experimental and numerical validation are reviewed. Next, the domains of applicability of each solution are studied, some simplifications suitable to steel pipelines are introduced, and an analytical model for the remaining strength of corroded steel pipelines is presented. This analytical solution is compared with the standards most widely used in the industry for assessment of corroded pipelines: ASME B31G, modified ASME, and DNV RP-F101. The empirical and analytical solutions are compared with respect to their most relevant parameters: critical (or flow) stress, flaw geometry parameterization, and Folias or bulging factor formulation. Finally, two common pipeline steels, API 5L grades X42 and X100, are selected to compare the different corrosion assessment methodologies. Corrosion defects of 75%, 50%, and 25% thickness reduction are evaluated. None of the experimental equations take into account the strain-hardening behavior of the pipe material, and therefore, they cannot properly model materials with very dissimilar plastic behavior. The comparison indicates that the empirical methods underestimate the remaining strength of shallow defects, which might lead to unnecessary repair recommendations. Furthermore, it was found that the use of a parameter employed by some of the empirical equations to model the assumed flaw shape leads to excessively optimistic and nonconservative results of remaining strength for long and deep flaws. Finally, the flaw width is not considered in the experimental criteria, and the comparative results suggest that the empirical solutions are somewhat imprecise to model the burst of wide flaws.
Effect of Endwall Contouring on a Transonic Turbine Blade Passage: Heat Transfer Performance
Authors: Panchal Kapil V. , Abraham Santosh , Roy Arnab , Ekkad Srinath V. , Ng Wing , Lohaus Andrew S. , Crawford Michael E.
Published: August 2016

Effect of turbine endwall contouring on its aerodynamic performance has been widely studied, but only a few studies are available in the open literature investigating its effect on heat transfer performance; especially at transonic exit Mach number conditions. In this paper, we report a study of effect of contouring on endwall heat transfer performance of a high-turning high-pressure (HP) turbine blade passage operating under transonic exit conditions. The paper describes comparison of heat transfer performance of two contoured endwall geometries, one aerodynamically optimized (AO) and the other heat transfer optimized (HTO), with a baseline, noncontoured geometry. The endwall geometries were experimentally investigated at Virginia Tech's transient, blow down, transonic linear cascade facility at three exit Mach numbers, Mex= 0.71, 0.88(design) and 0.95, for their heat transfer performance. Endwall surface temperatures were measured using infrared (IR) thermography and local heat transfer coefficient (HTC) values were calculated using measured temperatures. A camera matrix model-based data postprocessing technique was developed to relate the two-dimensional images captured by IR camera to three-dimensional endwall contours. The measurement technique and the methodology for postprocessing of the heat transfer coefficient data have been presented in detail. Discussion and interpretation of experimental results have been augmented using aerodynamic CFD simulations of the geometries. Both the contoured endwalls demonstrated a significant reduction in the overall average heat transfer coefficient values of the order of 10%. The surface Stanton number distributions also indicated a reduction in the level of hot spots for most of the endwall surface. However, at some locations an increase was also observed, especially in the area near the leading edge (LE). The results indicate that the endwall contouring could significantly improve heat transfer performance of turbine passages.
A Novel Approach to the Design and Development of an Interactive Learning App for Automotive In-Vehicle Infotainment Systems
Authors: Chen Yifan , Tonshal Basavaraj , Mitra Pramita , Simonds Craig , Aldighieri Paul
Published: August 2016

This paper presents the design, architecture, and implementation of “MyFord Touch Guide,” a novel, cross-platform mobile app that delivers an interactive and experiential learning experience for the Ford SYNCTM with MyFord TouchTM in-vehicle infotainment (IVI) system. This app incorporates the production of MyFord Touch graphical user interface for an interactive learning experience. Additionally, it integrates a host of video tutorials featuring a computer-animated character, which offers an insightful, self-guided tour experience of the essential features and functions of the system. MyFord Touch Guide is a cross-platform app and based on a “hybrid” app architecture that uses both native mobile and web technologies. Feedbacks gathered from multiple nation-wide surveys indicated that our approach was effective as an interactive, mobile learning app.
A Numerical Study of Francis Turbine Operation at No-Load Condition
Authors: Hosseinimanesh Hossein , Devals Christophe , Nennemann Bernd , Reggio Marcelo , Guibault François
Published: August 2016

This paper presents a numerical methodology to study Francis turbines at no-load condition, an important operating condition regarding static and dynamic stresses. The proposed methodology uses unsteady Reynolds-averaged Navier–Stokes (RANS) simulations that have been integrated with a user subroutine to compute and return the value of runner speed, time step, and friction torque. The modeling tool is the commercial software ansys-cfx 14. The research compares the simulations that were performed using transient rotor–stator (TRS) and stage interface models and validate the results through experiments over the full range of admissible guide vane angles (GVAs). Both TRS and stage interface models yielded similar trends for all turbine runner parameters during the no-load process. Results show sizable differences in the average and maximum pressure on the blades between TRS and stage simulations. Analysis of the flow behavior in TRS simulation demonstrates complex flow phenomena involving a vortex breakdown within the draft tube, and strong vortices blocking the runner inlet, which dissipate the input energy into the turbine and yield a near zero-torque at no-load condition.
Dual Combination Synchronization of the Fractional Order Complex Chaotic Systems
Authors: Singh Ajit K. , Yadav Vijay K. , Das S.
Published: August 2016

In this article, the authors have proposed a novel scheme for the dual combination synchronization among four master systems and two slave systems for the fractional order complex chaotic systems. Dual combination synchronization for the integer order has already been investigated in real space; but for the case of fractional order in complex space, it is the first of its kind. Due to complexity and presence of additional variable, it will be more secure and interesting to transmit and receive signals in communication theory. Based on the Lyapunov stability theory, six complex chaotic systems are considered and corresponding controllers are designed to achieve synchronization. The special cases, such as combination synchronization, projective synchronization, complete synchronization, and many more, can be derived from the proposed scheme. The corresponding theoretical analysis and numerical simulations are shown to verify the feasibility and effectiveness of the proposed dual combination synchronization scheme.
Open-Cell Metallic Porous Materials Obtained Through Space Holders—Part II: Structure and Properties. A Review
Authors: Stanev Lenko , Kolev Mihail , Drenchev Boris , Drenchev Ludmil
Published: August 2016

This work presents an overview of structural characteristics and basic mechanical properties of the open-cell metallic foams obtained by different space-holder methods, which are discussed in Part I of the same review. The presentation is arranged with respect to foam material, and the structure and properties are compared for different space holders and production techniques. In order to have more clear information for the structures obtained and their relation with production techniques, many images are provided and discussed. Compressive behavior of the foams is shown, and stress–strain curves are analyzed with respect to the energy absorption characteristics. The analysis are made on the basis of different porosities and processing parameters. Some applications of the open-cell metallic foams are discussed in the end of the article.
Mechanical Properties of Female Reproductive Organs and Supporting Connective Tissues: A Review of the Current State of Knowledge
Authors: Baah-Dwomoh Adwoa , McGuire Jeffrey , Tan Ting , De Vita Raffaella
Published: August 2016

Although there has been an upsurge of interest in research on women's sexual and reproductive health, most of the research has remained confined to the obstetrics and gynecology disciplines, without knowledge flow to the biomechanics community. Thus, the mechanics of the female reproductive system and the changes determined by pregnancy, age, obesity, and various medical conditions have not been thoroughly studied. In recent years, more investigators have been focusing their efforts on evaluating the mechanical properties of the reproductive organs and supportive connective tissues, but, despite the many advances, there is still a lot that remains to be done. This paper provides an overview of the research published over the past few decades on the mechanical characterization of the primary female reproductive organs and supporting connective tissues. For each organ and tissue, after a brief description of the function and structure, the testing methods and main mechanical results are presented. Constitutive equations are then reviewed for all organs/tissues together. The goal is to spark the interest of new investigators to this largely untapped but fast-evolving branch of soft tissue mechanics that will impact women's gynecologic, reproductive, and sexual health care.
Blister Testing for Adhesion Strength Measurement of Polymer Films Subjected to Environmental Conditions
Authors: Mahan Kenny , Rosen David , Han Bongtae
Published: August 2016

A blister testing procedure combined with a numerical procedure can be used effectively for characterizing the adhesion strength. A challenge arises when it is implemented after subjecting samples to various environmental conditions. The concept of pseudoproperty is introduced to cope with the problem associated with property changes during environmental testing. The pseudoproperty set is determined directly from a deflection versus pressure curve obtained from a typical blister test. A classical energy balance approach is followed to evaluate the energy release rate from the critical pressure and pseudoproperty set. The proposed approach is carried out for an epoxy/copper interface after subjecting samples to full moisture saturation and a high temperature storage condition. In spite of significant change in property, the energy release rates are calculated accurately without extra tests for property measurements.
Experimental Study on Installation of Composite Bucket Foundations for Offshore Wind Turbines in Silty Sand
Authors: Zhang Puyang , Zhang Zhi , Liu Yonggang , Ding Hongyan
Published: August 2016

The composite bucket foundation (CBF) is a cost-competitive foundation for offshore wind turbines, which can be adapted to the loading characteristics and development needs of offshore wind farms due to its special structural form. There are seven sections divided inside the CBF by steel bulkheads, which are arranged in a honeycomb structure. The six peripheral sections with the skirt have the same proportions while the middle orthohexagonal one is a little larger. With the seven-section structure, the CBF has reasonable motion characteristics and towing reliability during the wet-tow construction process. Moreover, the pressure inside the compartments can control the levelness of the CBF during suction installation. Several large-scale model tests on suction installation of CBF have been performed in order to explore the feasibility of the tilt adjusting technique in saturated silty sand off the coast of Jiangsu in China. The composite bucket foundation in the tests has an outer diameter of 3.5 m and a clear wall height of 0.9 m. During the suction-assisted penetration process, the pressures in all the compartments were controlled to level the foundation in a timely operation. A convenient method is to improve the CBF inclination by controlling the inside differential pressure among the compartments. It can be commonly carried out by applying suction/positive pressure with intermittent pumping among the seven compartments. Another adjusting technique for a big tilt with deeper penetration is operated with decreasing the penetration depth achieved by suction-assisted lowering the relatively high compartments and positive pressures raising the relatively low compartments. Test results show that the reciprocating adjustment process can be repeated until the CBF is completely penetrated into a designed depth.
Monitoring Pump Parameters in Small Modular Reactors Using Electric
Motor Signatures
Authors: Upadhyaya Belle R. , Mehta Chaitanya , Wesley Hines J. , Lollar Victor B. , Bayram Duygu
Published: August 2016

Small modular nuclear reactors (SMRs) are designed for long-term operation with minimum outages and for possible deployment in remote locations. To achieve this operational goal, the SMRs may require remote and continuous monitoring of performance parameters that contribute to operation and maintenance. This feature is also important in monitoring critical parameters during severe accidents and for postaccident recovery. Small integral light water reactors have in-vessel space constraints, and many of the traditional instrumentation are not practical in these systems. To investigate this issue, analytical and experimental researches were carried out using a flow test loop to characterize the relationship among process variables (flow rate and pressure) and pump motor signatures. The findings of this research are presented, with implications in relating electrical signatures to pump parameters. The relationship between the electrical signatures and the process variables is discussed with reference to the experimental results. The results of this work may be used for monitoring process variables in small modular reactor systems.
Mechanical Energy Change in Inertial Reference Frames
Authors: Ghanbari Saeed
Published: August 2016

The mechanical energy change of a system in an inertial frame of reference equals work done by the total nonconservative force in the same frame. This relation is covariant under the Galilean transformations from inertial frame S to S′, where S′ moves with constant velocity relative to S. In the presence of nonconservative forces, such as normal and tension forces, the mechanical energy of a system can be conserved in S and not be conserved in S′. In this paper we find useful relations between the mechanical energy changes in two inertial frames of reference.
Acoustics for the Deaf: Can You See Me Now?
Authors: Vongsawad Cameron T. , Berardi Mark L. , Neilsen Tracianne B. , Gee Kent L. , Whiting Jennifer K. , Lawler M. Jeannette
Published: August 2016

Although acoustics examples and demonstrations can be an effective tool for engaging students in introductory physics classes and outreach, teaching principles of sound and vibration to the deaf and hard of hearing needs to be approached carefully. The deaf and hard of hearing have less intuition with sound but are no strangers to some of the effects of pressure, vibrations, and other basic principles that are related to sound. We recently expanded our “Sounds to Astound” outreach program and developed an acoustics demonstration program for 80 visiting deaf students mostly between the ages of 13 and 18. Both this experience, which had a “See and Feel” approach, similar to what was proposed by Lang, and a specialized planetarium program helped reinforce for the students the opportunities that exist for them in higher education. This paper describes some of the pedagogical underpinnings, the demonstrations, their implementation and lessons learned, and student responses.