bluuebunny/crossref_metadata_2025 huggingface dataset:
Correction for the taxonomy of Trichomanes foeniculaceum as synonym of Abrodictyum parviflorum (Hymenophyllaceae, Polypodiidae)
Authors: DUBUISSON JEAN-YVES , HENNEQUIN SABINE
Published: January 2019

In Dubuisson et al. (2017), Trichomanes foeniculaceum (Hooker 1845: 135) is cited as a heterotypic synonym of Abrodictyum parviflorum (Poiret 1808: 83) Bauret & Dubuisson (2017: 211), which was newly combined and proposed as the valid name of Abrodictyum meifolium (Bory ex Willdenow 1810: 509, 510) Ebihara & Dubuisson (2006: 144), a widespread species in the western Indian Ocean. The proposed authorship for T. foeniculaceum in Dubuisson et al. (2017) (i.e., Hooker 1845: 135) was in accordance with the Tropicos database (www.tropicos.org; as consulted in 2017) and Roux (2009). However, the valid author is actually Bory ex Willdenow (1810: 511), as also reported in IPNI (www.ipni.org) and by Tardieu-Blot (2008). We propose thus hereafter the corrected taxonomy for A. parviflorum including T. foeniculaceum as a synonym.
Taxonomy, evolution and phylogeography of the genus Helonias (Melanthiaceae) revisited
Authors: TANAKA NORIYUKI
Published: January 2019

This paper reviews the taxonomy, evolution and phylogeographic aspects of the genus Helonias L. sensu lato, including Ypsilandra and Heloniopsis (Melanthiaceae) that are basically similar in many morphological and ecological characters to Helonias sensu stricto. It includes three parts, I–III. In Part I, characters and their variation are examined to determine generic traits and diversity. In Part II, an attempt is made to taxonomically determine diversity among individuals. Taxonomic conclusions and revisions are principally the following: Helonias comprises 12 species, which are classified into two sections, H. sect. Helonias and H. sect. Heloniopsis comb. & stat. nov. Helonias sect. Helonias consists of H. bullata only; H. sect. Heloniopsis comprises two subsections, H. subsect. Ypsilandra comb. & stat. nov. and H. subsect. Heloniopsis. Helonias subsect. Ypsilandra is composed of five species previously published under the genus Ypsilandra. Helonias subsect. Heloniopsis consists of two series, H. ser. Umbellatae ser. nov., with three species from Taiwan and the Nansei Islands (incl. the Ryukyus), Japan, and H. ser. Heloniopsis, with three species from Japan, Korea and E. Russia (southern Sakhalin). Helonias yunnanensis var. mesostyla is described as a new variety from N Myanmar and SW China (NW Yunnan). The new combinations Helonias koreana (from Korea) and H. parviflora (from China) are proposed. Lectotypes for Ypsilandra parviflora, Y. thibetica, Y. yunnanensis var. micrantha, Heloniopsis breviscapa and H. grandiflora are designated. A revised typification for Sugerokia japonica is proposed, negating a previous lectotypification. Heloniopsis tubiflora is reduced to synonymy under Helonias koreana. In Part III, the evolutionary and phylogeographic aspects of Helonias are discussed, and a phylogram inferred from cladistic analysis of phenotypic characters is presented. In the phylogram, Helonias is monophyletic, while H. sect. Helonias and H. subsect. Ypsilandra are respectively paraphyletic, and H. subsect. Heloniopsis is monophyletic. Incongruence in results between morphological and DNA sequence analyses is briefly discussed.
Description of a new water mite species of the genus Lebertia Neuman, 1880 (Acari, Hydrachnidae: Lebertiidae) from Russia
Authors: TUZOVSKIJ PETR V.
Published: January 2019

The fauna of the genus Lebertia collected in Russia currently includes about 50 species (Sokolow 1940, Wainstein & Tuzovskij 1974, Tuzovskij1982a, b, 1990, 2011a, b, 2012, Tuzovskij & Semenchenko2009, Semenchenko & Tuzovskij 2010). In this paper a new water mite species of the genus Lebertia is described.
Four new species of the genus Paraustrorhynchus (Rhabdocoela: Kalyptorhynchia: Polycystididae)
Authors: LIN YITAO , REYGEL PATRICK , FENG WEITAO , CHEN JIAJIA , TESSENS BART , VAN STEENKISTE NIELS W. L. , SCHOCKAERT ERNEST R. , ARTOIS TOM J. , WANG ANTAI
Published: January 2019

Four new species of Paraustrorhynchus (Rhabdocoela: Kalyptorhynchia: Polycystididae) are described: two from Southern China (P. shenda n. sp., P. sinensis n. sp.), one from New Caledonia (P. isoldeae n. sp.), and one from India (P. smeetsae n. sp.). All four species show a typical dark blue dorsal pigmentation pattern, which is unique to the genus. This pigment forms a broad longitudinal line in P. shenda n. sp. and P. sinensis n. sp., shows an additional transverse band at the level of the pharynx in P. smeetsae n. sp. and forms a Y-shaped pattern in P. isoldeae n. sp. The four species can also be distinguished from each other and their congeners by the detailed morphology of the hard parts of the male system, which in all cases consists of an L-shaped (P. shenda n. sp., P. isoldeae n. sp) or slightly-curved (P. smeetsae n. sp., P. sinensis n. sp.) prostate stylet type II and a prostate stylet type III, which consists of three plates: a basal plate from which two longer plates depart, each with a distal serrated rim. A phylogenetic analysis based on 18S and 28S-rDNA data indicates that Paraustrorhynchus is a monophyletic taxon within Polycystidinae, with Alcha evelinae as the sister group.
Tests for Scale Parameter of Asymmetric Log Laplace Distribution
Authors: Khandeparkar Pradnya P. , Dixit V. U.
Published: January 2019

This article focuses on tests for scale parameter of asymmetric log Laplace distribution when shape parameters are known. The most powerful test is obtained for scale parameter and is compared with the corresponding uniformly most powerful (UMP) test based on distribution of order statistic. A simple ad hoc test based on sample median is also suggested and is compared with the other two tests.

AMS 2000 subject classification: 62F03
Retrobulbar Sinus Injection of Doxorubicin is More Efficient Than Lateral Tail Vein Injection at Inducing Experimental Nephrotic Syndrome in Mice: A Pilot Study
Authors: Bohnert Bernhard N. , Dörffel Thomas , Daiminger Sophie , Calaminus Carsten , Aidone Sandro , Falkenau Almuth , Semrau Antje , Le Mai J. , Iglauer Franz , Artunc Ferruh
Published: January 2019

Doxorubicin-induced nephropathy in mice is a model for studying experimental nephrotic syndrome. It corresponds to puromycin aminonucleoside nephrosis in rats. In this model, susceptible 129 S1/SvImJ mice are administered a rapid intravenous injection that can be accomplished via either the lateral tail vein or the retrobulbar sinus. Because doxorubicin is a highly toxic substance, extravasation must be avoided during the administration of the intravenous injection to prevent the development of large necrotizing lesions and exacerbation of the animals’ stress. In the present study, we compared the safety and stress of these two injection routes by using histopathological analyses of the animals’ orbital cavities or tails, respectively. The injection of 14.5 µg/g body weight doxorubicin into the mice’s lateral tail veins ( n = 9) or retrobulbar sinuses ( n = 19) caused no clinically detectable stress or impairment. Histopathologies of the specimens five days after doxorubicin injection revealed inflammatory lesions at the injection sites in both groups. In the orbital sinus specimens from the retrobulbar-injected group, fibrosis was evident 25 days after injection. Moreover, while all of the retrobulbar-injected mice (100%) developed nephrotic syndrome, tail vein-injected mice had a significantly lower response rate (66%, p = 0.047, Fisher’s exact test) and exhibited only attenuated features of nephrotic syndrome. It was therefore concluded that doxorubicin administration via either lateral tail vein or retrobulbar sinus injections led to a similar induction of histopathological changes with no effects on the clinical well-being of the mice. However, retrobulbar sinus injections were more efficient for inducing experimental nephrotic syndrome.
Simulation Rhetoric and Activity Theory: Experiential Learning in Intercultural Simulations
Authors: Wang Junhua
Published: January 2019

In the field of intercultural business and technical communication, intercultural communication has been a regular topic in curriculum for decades; various teaching approaches exist for developing students’ cultural awareness and helping them achieve a theoretical understanding about the concept of culture, cultural differences, and cultural conflict. But quite often teaching and learning are limited in the classroom context, although it is true that study abroad programs are available for a small group of students. As a result, students do not have enough opportunities to interact with members of other cultures, which limits students’ potentials for gaining intercultural competence. This study explores the rhetorical nature of simulations, defines the perspective of using activity theory as a framework to understand the learning process occurring in simulations, and provides an intercultural simulation example to explain how instructors can incorporate simulations into the business and technical communication curriculum.
The Essential Ambiguity of the Social
Authors: Green Bryan
Published: January 2019

Methodological divisions in sociology, the study of the social, are not just deep and persistent but patterned—most obviously in the separate development of qualitative methods in ethnography and grounded theory, but also in subsidiary divisions within those separations, following the same pattern. The pattern being too deep-rooted to be explained as empirical happenstance, it will be explored here as the effect of an equally deep-rooted condition. More exactly, through postulating that sociology’s subject-matter, the social, is ontologically rooted in an essential ambiguity between abstraction and individuation. Four criteria are drawn from the idea of the dichotomy being constitutively essential, which this or any alternative candidates must meet. The article conducts the postulate through the criteria, and applies the criterion of separating better from worse sociological theory to the work of Pierre Bourdieu.
Leveraging Cumulative Network Meta-analysis and Value of Information Analysis to Understand the Evolving Value of Medical Research
Authors: Kim David D. , Trikalinos Thomas A. , Wong John B.
Published: January 2019

Background. Leveraging cumulative network meta-analysis (NMA) and value of information (VOI) analysis, this article aims to understand the evolving value of medical research and to identify gaps in the evidence for future research. Methods. As an illustration, we identified 31 randomized controlled trials (RCT) from 1980 to 2013 that examined a network of 3 interventions for coronary artery disease: medical therapy (MED), percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG) surgery. We conducted Bayesian NMA to combine evidence from a new RCT with existing knowledge. Then, using the Duke Databank for Cardiovascular Diseases database, we developed an accelerated failure time model to estimate the joint effects of patient characteristics and treatment choices on survival outcomes. With the estimated coefficients and covariance matrices, we projected survival benefits and its surrounding uncertainty among 50,000 simulated patients treated with MED, PCI, or CABG. The value of resolving residual uncertainty from future trials was quantified through the VOI analysis. We repeated these steps for each published RCT to estimate dynamic changes in VOI estimates. Results. Our cumulative NMA found that CABG conferred a lower, but not statistically significant, mortality than PCI (hazard ratio [HR], 0.90; 95% uncertainty interval, 0.80–1.05). MED had a nonsignificantly higher long-term mortality than PCI (HR, 1.11; 0.98–1.31) but significantly higher than CABG (HR, 1.07; 1.23–1.41). The greatest potential gains from future research would come from additional head-to-head trials between CABG v. PCI with the value of future research equaling 0.27 life years per patient. Conclusions. The combination of cumulative NMA and VOI approaches can improve the efficiency of comparative effectiveness research by using all of the available evidence to determine future research priorities.
Food skills group value, meaning, and use with inpatients in a mental health setting
Authors: De Vos Gina , Leclair Leanne
Published: January 2019

Introduction

Occupational therapists use food skills groups to support mental health recovery and engagement in meaningful occupation. Research examining participants’ experiences in these mental health groups is sparse.

Method

Researchers used a convergent parallel mixed methods design. Following participation in an inpatient food skills group, 60 participants completed a questionnaire, and 20 also participated in a semi-structured interview. The questionnaire data was analysed using descriptive and correlational statistics. The interview data was analysed using thematic analysis. Triangulation was used to combine and interpret findings from the different methods to gain a more complete understanding of the participants’ experiences.

Findings

Participants strongly agreed/agreed that they enjoyed participating, felt having the opportunity to participate was important to their recovery, and after discharge would use the skills they had learnt. Age, sex, and level of education were associated with some of the questionnaire responses. Three main themes emerged from the interview data: importance of engaging/doing, connections with food, and being involved in a group process.

Conclusion

Individuals who participated in the food skills group valued having the opportunity to build skills and engage in meaningful activities with others while in hospital. They identified the food skills group as important to their recovery.
Influence of land cover on lightning and convective precipitation over the European continent
Authors: Rivas Soriano L , Sánchez Llorente JM , González Zamora A , de Pablo Dávila F
Published: January 2019

The impact of land cover on lightning and convective precipitation in the summertime over Europe was analysed using five-year data. Lightning data were obtained with the Optical Transient Detector (OTD) at a 0.5° × 0.5° spatial resolution and the convective precipitation data were calculated by the NCEP/DOE AMIP-II Reanalysis at a ∼1.9° × 1.9° spatial resolution. Data concerning land cover were obtained from the Global Land Cover Facility, although the original 14 categories were grouped into seven categories (water, forest, shrubland, grassland, cropland, bare ground and urban). For all latitude ranges, forested areas tend to increase convective activity during the warm period of the year, and the general effect of shrubland areas is to suppress convective activity. The behaviour of convection in relation to grasslands and croplands depends on latitude. At low latitudes both vegetation types tend to increase convection during the summer. At high latitudes, grassland and cropland areas appear to be associated with the opposite effect in relation to convection: grass suppresses and crops enhance it. Finally, bare soil tends to decrease convective activity. These results seem to be related to the impact of vegetation on soil moisture and roughness. In general, vegetation areas associated with high soil moisture contents and high values in roughness length tend to enhance convective activity.
The use of Aperiodic Analysis of the EEG during Carotid Artery Surgery
Authors: Silbert B. S. , Koumoundouros E. , Davies M. J. , Cronin K. D.
Published: January 2019

A new processed EEG machine, the Lifescan, ® which uses aperiodic analysis, was used to monitor cerebral activity prospectively in twenty-one patients undergoing carotid artery surgery under general anaesthesia. The machine was easy to apply, use and read. Volatile agents caused a bilateral decrease in high frequency activity. Unilateral changes consistent with cerebral ischaemia at the time of carotid cross-clamping were also seen. One such prolonged change was not associated with neurological deficit. A further patient awoke with neurological deficit without displaying Lifescan® evidence of ischaemia. The machine requires further assessment.
Dorsal Nerve of Penis Block — Anatomical and Radiological Studies
Authors: Brown T. C. K. , Weidner N. J. , Bouwmeester J.
Published: January 2019

Dorsal nerve of penis block is becoming more widely used for circumcision in infants and children. Various techniques have been described. This paper presents a detailed study of the anatomy involved based on anatomical dissections and radiological studies. Complications and their possible causes are discussed.
Epidural Pethidine or Fentanyl during Caesarean Section: A Double-Blind Comparison
Authors: Paech M. J.
Published: January 2019

The onset, quality and duration of analgesia and side-effects of a single bolus dose of either epidural pethidine 50 mg or fentanyl 100 mcg, administered immediately post-delivery, were compared in a randomised, double-blind study of fifty-five women undergoing epidural caesarean section. The onset of effect was more rapid with fentanyl, a significantly larger number of women achieving complete pain relief fifteen minutes post-administration (P<0.05). The quality of analgesia was good in both groups and the quality and duration of effective analgesia not significantly different. The incidence and severity of side-effects were low, with no significant difference between groups. One patient in the pethidine group experienced early onset respiratory depression; however, she did not require active treatment.

Epidural fentanyl 100 mcg appears to offer a small clinical advantage over pethidine 50 mg for intraoperative use during caesarean section.
An Occasional Segment Presenting Reports of Clinical Investigation and Experience in the Pacific Island Region
Authors: Oberoi G. S. , Yaubihi N.
Published: January 2019

In order to introduce the technique of epidural narcotics for pain relief in Papua New Guinea, fifty patients were given low doses of epidural morphine and thereupon the quality of analgesia and morbidity evaluated. The lowest effective epidural morphine dose was determined by considering the patient's characteristics and height of surgical incision. Pain relief was provided for three postoperative days in the surgical or gynaecological wards. The quality of analgesia thus provided was excellent in all the patients with no incidence of clinically significant respiratory depression or hypotension. Minor complications such as nausea, vomiting, pruritis and retention of urine were also relatively uncommon.
The Value of Prepositioning in Smartphone-Based Vanpool Services under Stochastic Requests and Time-Dependent Travel Times
Authors: Li Donghui , Antoniou Constantinos , Jiang Hai , Xie Qianyan , Shen Wei , Han Weijian
Published: January 2019

One of the fundamental issues in dynamic vanpool services is to schedule a fleet of vans to serve passengers efficiently, which is usually modeled as the dynamic and stochastic dial-a-ride problem (DARP) in recent studies. However, these studies do not consider prepositioning when dispatching the vans. Prepositioning means positioning the vans in advance to satisfy potential future requests, instead of only considering sending the vans to requests received. This study developed a metaheuristic scheduling algorithm for the dynamic and stochastic DARP. The algorithm uses multiple scenarios which include future requests and traffic conditions to generate and evaluate potential decisions considering prepositioning. The study uses a real dataset, which includes requests from a vanpool services provider and traffic conditions achieved from an online map service, to test the algorithm. The results show that incorporating stochastic requests without considering prepositioning can improve the average profit by 18.6% and that prepositioning can improve average profit by 23.8% and reduce average waiting time by 74.7%. The influence of different algorithm parameters is tested to provide guidance for the practical usage of the proposed algorithm.
Safety Impacts of Signing and Pavement Markings on Property-Damage-Only Crashes at Multi-Lane Roundabouts
Authors: Johnson Mark T.
Published: January 2019

Conventional intersections that have been replaced by multi-lane roundabouts have experienced a substantial reduction in both injury and fatal crashes. Property-damage-only (PDO) crashes have also been reduced at some of these roundabouts. However, some have experienced a significant increase in PDO crashes. This has caused some jurisdictions to question the suitability of multi-lane roundabouts despite their benefit of reduced injury and fatal crashes. The question arises as to why some U.S. multi-lane roundabouts have high numbers of PDO crashes whereas other outwardly similar roundabouts do not. This paper examines the hypothesis that the cause of the higher numbers of PDO crashes at some U.S. multi-lane roundabouts is driver confusion and information overload, arising from a combination of poor geometric layout, signing, and pavement markings. Successful roundabout design requires that the geometric layout, the signing, and the pavement markings act together to give a simple, clear message to the drivers, thereby avoiding driver confusion and reducing PDO crashes. This paper reviews research and explores the best practice for roundabout signing and pavement marking using established traffic engineering principles and discusses aspects of the 2009 Manual on Uniform Traffic Control Devices that may contradict these principles. The paper highlights two case studies of poorly performing U.S. multi-lane roundabouts, where the revised signing and pavement markings achieved 37–80% reduction in PDO accidents.
Importance-Performance Analysis in Public Transportation: Methodological Revision for Practical Implementation
Authors: Rodriguez-Valencia Alvaro , Rosas-Satizabal Daniel , Paris David
Published: January 2019

Importance-performance analysis (IPA) is a common and accepted method used by service industries to improve their service and therefore increase customer satisfaction. In public transportation, it has been adopted to assess the attributes of transit system. To analyze the practical implementation of IPA in transit user satisfaction studies, an extensive literature review was carried out to identify challenges. Unlike the “performance” dimension, measuring “importance” is challenging, given the wide variety of approaches and specific methods. For practical application, choosing a specific method in a specific approach has diverse implications. Real-world transit user satisfaction surveys of three different bus transit (sub) systems in Bogotá were used to try, test, and compare results, methods, applications, and—from a practical perspective—to identify the pitfalls, risks, difficulties, advantages, and biases of using different techniques to measure importance in relation to public transportation services. At the end of the paper, the advantages and shortcomings of different importance measurement methods are synthesized, and easy-to-implement suggestions for practitioners are provided.
Effect of Night Time Eating on Postprandial Triglyceride Metabolism in Healthy Adults: A Systematic Literature Review
Authors: Bonham Maxine P. , Kaias Elleni , Zimberg Iona , Leung Gloria K. W. , Davis Rochelle , Sletten Tracey L. , Windsor-Aubrey Hazel , Huggins Catherine E.
Published: January 2019

Eating at night time, as is frequent in shift workers, may contribute to increased cardiovascular disease (CVD) risk through a disruption in usual lipid metabolism, resulting in repeated and sustained hyperlipidemia at night. This systematic review aimed to investigate the impact of eating a meal at night compared with the same meal eaten during the day on postprandial lipemia. Six databases were searched: CINAHL Plus, Cochrane Library, EMBASE, Ovid MEDLINE, Informit, and SCOPUS. Eligible studies were original research cross-over design with a minimum fasting period of 5 h before testing preceded by a standardized control meal; measured postprandial triacylglycerol (TAG) for 5 h or greater; had meal time between 0700 h and 1600 h for day time and between 2000 h and 0400 h for night time; and had within-study test meals (food or drink) that were identical in macronutrient composition and energy. Two authors independently completed eligibility and quality assessment using the American Dietetic Association Quality Criteria Checklist for Primary Research. After removing duplicates, 4,423 articles were screened, yielding 5 studies for qualitative synthesis. All studies identified at least one parameter of the postprandial TAG response that was different as a result of meal time (e.g., the total concentration or the time course kinetics). Two studies reported a greater total TAG concentration (area under curve) at night compared with day, and 3 studies found no difference. Four studies reported that the kinetics of the postprandial time course of TAGs was different at night compared with during the day. Inconsistent reporting in the primary studies was a limitation of the review. Night eating may negatively affect postprandial lipemia and this review shows there is a need to rigorously test this using standardized methods and analysis with larger sample sizes. This is critical for informing strategies to lower CVD risk for shift workers.
Mortality and Prognostic Prediction in Very Elderly Patients With Severe Pneumonia
Authors: Baek Moon Seong , Park Sojung , Choi Jeong-Hee , Kim Cheol-Hong , Hyun In Gyu
Published: January 2019

Introduction:

Although prognostic prediction scores for pneumonia such as CURB-65 score or pneumonia severity index (PSI) are widely used, there were a few studies in very elderly patients. The aim of the study was to validate prognostic prediction scores for severe pneumonia and investigate risk factors associated with in-hospital mortality of severe pneumonia in very elderly patients.

Methods:

During the 6-year study period (from October 2012 to May 2018), 160 patients aged 80 or older admitted to medical intensive unit were analyzed retrospectively. Pneumonia severity was evaluated using CURB-65 score, PSI, Sequential Organ Failure Assessment (SOFA) scores, A-DROP, I-ROAD, UBMo index, SOAR score, and lactate. The outcome was in-hospital mortality.

Results:

The median age was 85 years (interquartile range: 82-88). Nursing home residents accounted for 71 (44.4%) and in-hospital mortality was 40 (25.0%). Logistic regression showed that chronic lung, mechanical ventilation, hemodialysis, and albumin were associated with in-hospital mortality of pneumonia. Using the receiver operating characteristics curve for predicting mortality, the area under the curve in pneumonia was 0.65 for the SOFA score, 0.61 for the CURB-65 score, 0.52 for the PSI, 0.58 for the A-DROP, 0.52 for the I-ROAD, 0.54 for UBMo index, 0.59 for SOAR score, and 0.65 for lactate.

Conclusion:

The performances of the CURB-65 and PSI are not excellent in very elderly patients with pneumonia. Further studies are needed to improve the performance of prognostic prediction scores in elderly patients.
Exploring the Impact of Child Maltreatment and Interparental Violence on Violent Delinquency in an International Sample
Authors: Steketee Majone , Aussems Claire , Marshall Ineke Haen
Published: January 2019

Young people are exposed to violence regularly in their homes, schools, and communities. Such exposure can cause them significant physical, mental, and emotional harm, with long-term effects lasting well into adulthood. Of particular concern is violence within the family, where children are victimized by their parents. Research shows that direct and indirect childhood exposure to violence and maltreatment within the family increases the risk of subsequent violent delinquent behavior. Social learning theory and attachment theory place parenting at the center of the “cycle of violence,” and “intergenerational transmission of violence” claims that experiencing violence in childhood will lead to the perpetration of violence in adolescence. Although much research has been done, these assertions have never been tested on a large international sample of young people. The current article fills this void by analyzing surveys completed by 57,892 students who were 12 to 16 years old from 25 countries as part of the International Self-Report Delinquency Study (ISRD3). Structural equation modeling (SEM) is used to test the direct and indirect effects of child maltreatment and interparental violence on self-reported violent delinquency. Mediating effects are proposed for attachment to parents, parental social control (measured by parental knowledge, parental monitoring, and child disclosure), and parental moral authority. Analysis suggests direct effects of child maltreatment and interparental violence, as well as mediating effects of parental monitoring, parental knowledge, and parental moral authority. Child disclosure and attachment to parents do not affect violent juvenile offending. Being a victim of both child maltreatment and interparental violence is found to exacerbate the effect on violent offending. The results support the cross-national generalizability of the “cycle of violence” argument that children tend to reproduce the behavior of their parents.
Optimization design of the key parameters of McPherson suspension systems using generalized multi-dimension adaptive learning particle swarm optimization
Authors: Gao Qi , Feng Jinzhi , Zheng Songlin
Published: January 2019

The performance parameters of suspension systems must be properly matched to ensure the handling and stability performance of a vehicle. Based on real vehicle measured data, a parameterized vehicle dynamic model is built, and the validity of the parameterized vehicle dynamic model is verified by comparing simulation results with real vehicle test results. Seven representative steady-state and transient single evaluation indicators of handling and stability of the vehicle are selected. The key parameters of McPherson suspension system, which significantly affects steady-state and transient handling and stability performance, are selected through a sensitivity analysis. Their contribution rates for each single evaluation indicator are calculated based on 81 simulation tests using the parameterized vehicle dynamic model. A comprehensive evaluation indicator system for the whole vehicle is established. This system contains the seven steady-state and transient single handling and stability evaluation indicators that are obtained using a quadratic response surface fitting for the selected key parameters. The comprehensive evaluation indicator system is used to show whether a vehicle has good steady-state and desirable transient responses. Moreover, a generalized multi-dimension adaptive learning particle swarm optimization is proposed to search for the global optimum of the comprehensive evaluation indicator system across the search space with rapid convergence. Optimization results show that a comprehensive handling and stability performance are improved, and simulation results of the parameterized vehicle dynamic model that is modified in accordance with the optimization results verify the improvement of the steady-state steering driving behavior and transient yaw response of the vehicle. In conclusion, the comprehensive evaluation indicator system is feasible, and the generalized multi-dimension adaptive learning particle swarm optimization is effective for the optimization design of the key parameters of the McPherson suspension system.
Deep Drawing of Plain Weft-Knitted Fabric Composites Part 2.: Strain Field Analysis
Authors: Lim T.C. , Ramakrishna S. , Shang H.M.
Published: January 2019

Previous modelling techniques in sheet forming of textile composites have focused on computational simulations due to the numerous computations involved. Recently a procedure for stretch forming analysis of plain weft-knitted fabric composites has been developed. The analytical model for the stretch forming process is now being extended for the deep drawing process in this paper. The theoretical strain field gives good approximation to the experimental results.
Fracture Characteristics of Knitted Fabric Composites under Tensile Load
Authors: Zhang Yanzhong , Bini T.B. , Huang Zheng Ming , Ramakrishna S.
Published: January 2019

This paper reports tensile properties of single layer and multilayer knitted glass fabric reinforced epoxy composites. The single layer composite was subjected to tensile load in off-axis angles of 0°, 30°, 45°, 60° and 90°. The multilayer laminates stacked as configurations of [0°]4, [07±4570°], [0°/90°/90°/0°] and [90°]4 were tested under a uniaxial tensile load. Emphasis was on the fracture characteristics of these composites. A ‘matrix digestion and layer peeling’ method was used to visualize the fracture modes of all the layers in a fractured laminate on a lamina level. It was found that the fracture mode of an angle-plied lamina in the laminate is different from that of a single layer composite under an off-axial tensile load.
A Study of the Effect of Surface Treatments on the Thermal Stability of Flax Fibres
Authors: Zafeiropoulos N. E. , Baillie C. A. , Matthews F. L.
Published: January 2019

There is an increasing interest in using natural fibres as reinforcing agents in composites. These fibres are considered to be a potential candidate to replace glass fibres in certain applications of composites. They have a number of advantages over glass fibres such as lower cost, lower density, non toxicity, re cycle ability and they are easier to process. However, natural fibres are not heat resistant like glass fibres and therefore they cannot be used with all polymer matrices. Furthermore, natural fibres are hydrophilic materials that do not adhere very well with most polymer matrices that are hydrophobic. Surface treatments are usually employed to improve adhesion in natural fibre composites. Nevertheless, the effect of these treatments upon the thermal stability of natural fibres has not been addressed sufficiently. In this letter seven grades of flax fibres were studied recently to determine their thermal stability profiles for potential use as reinforcements in composite materials. The results indicate that treated flax performs better than untreated flax. Acetylation and stearic acid treatments were found to increase the thermal stability of flax. Duralin flax was found to be sufficiently heat resistant to be usable with thermoplastics such as nylon 6, where the processing temperature is higher than it is for polyolefin matrices.
Ultraviolet curing of Glass Fibre Reinforced Polyester Composites
Authors: Yuan Qiang , Yang Ming-Bao , Mai Yiu-Wing
Published: January 2019

Light curing of fibre composites was studied to explore its usefulness as a cost-effective production technique without unacceptable sacrifices of mechanical properties. Knitted continuous glass fibre reinforced polyester composites were cured by ultraviolet light and vacuum bag resin infusion (VBRI). A maximum thickness of 13 mm could be achieved with this technique. The compressive strength was shown to be independent of laminate thickness; but both the flexural strength and modulus were reduced with increasing thickness of laminate. The impact damage was also studied using drop-weight impact tests. For the same impact energy imposed on the laminates, the delamination areas decreased with laminate thickness.
Fatigue Damage Mechanisms in Carbon-Epoxy Multi-Fibre Model Composites
Authors: Goutianos S. , Peijs T.
Published: January 2019

Polarised-light microscopy was used to investigate the influence of stress level and fibre/matrix adhesion on the fatigue failure process in carbon-epoxy multi-fibre model composites. It was shown that the fatigue stress has a strong influence on the damage accumulation process in such model composites. Increasing levels of tension-tension fatigue stress resulted in an increase in total number of fibre breaks, stronger fibre-fibre interaction, i.e. fibre failure due to stress concentrations caused by a fractured adjacent fibre, and more interfacial damage. An increase in fibre-matrix adhesion was also found to result in more fibre-fibre interactions, whereas in the case of poor fibre/matrix adhesion extensive debonding takes place. Finally, the experimental observations were interpreted using a 3-D finite element analysis of the model composites.
The Effect of Transcrystalline Interface on the Mechanical Properties of Polyethylene / Polyethylene Composites
Authors: Levitus D. , Kenig S. , Kazanci M. , Harel H. , Marom G.
Published: January 2019

The effect of the transcrystalline layer on the longitudinal properties of unidirectional polyethylene/polyethylene (PE/PE) composites was studied. Two sets of PE/PE composites were prepared by quenching and by isothermal crystallisation, respectively, using a wide range of fibre volume fractions. Quenching and isothermal crystallisation were expected, respectively, to prevent or to induce generation of a highly ordered transcrystalline layer. The experimental results showed that isothermal crystallisation produced a substantial positive effect on both the longitudinal strength and modulus, which was attributed to transcrystallinity.
The Effect of Transcrystallinity on the Interface of Green Flax/Polypropylene Composite Materials
Authors: Zafeiropoulos N. E. , Baillie C. A. , Matthews F. L.
Published: January 2019

In recent years there has been an increasing interest in using natural fibres as potential reinforcements for polymers. The introduction of fibres such as flax in a semicrystalline thermoplastic matrix such as iPP (isotactic polypropylene) has been shown to lead to the development of transcrystallinity. The presence of an anisotropic layer such as transcrystallinity in the composite material may in turn have a profound effect on the mechanical behaviour of the interface. In this study the role of transcrystallinity has been investigated in green flax (that is flax as received direct from the crops)/iPP by means of the fragmentation test. The results are discussed in terms of previously reported results for treated flax fibres (dew retted)/iPP. Transcrystallinity leads to a stronger interface in green flax/iPP, and its thickness affects the interfacial strength, with thinner transcrystalline layers giving a stronger interface. An examination of the mode of failure at the interface after the fragmentation test also supports the conclusion that the transcrystalline interface is stronger than the spherulitic interface in green flax/iPP composites.
Resole Resin as Sizing Agent for Aramid Fibres
Authors: Bousoulas J. , Tarantili P. A. , Andreopoulos A. G.
Published: January 2019

A comparative study was made in order to evaluate the interfacial characteristics of treated aramid fibres and epoxy resins. Surface treatment by coating with phenolic resins was performed using the following two systems: a) alkaline aqueous solution of resole resin and b) solution of novolac resin containing hexamethylene-tetramine as cross-linking agent. After these treatments, the modified aramid fibres were used for the preparation of reinforced epoxy specimens. The flexural properties of these specimens were determined and the results were discussed taking into consideration the surface characteristics of the modified fibres, as derived from pull-out tests and contact angle measurements. It was shown that both coatings are adequate to promote interfacial adhesive bonding to epoxy matrices due to the chemical reactivity of phenolic resins to the epoxy matrix as well as to their affinity with the aramid fibre surface. Resole appeared more efficient than novolac as it produces uniform continuous films, shows increased reactivity due to its higher hydroxyl content and can be easily processed because it is soluble in alkaline water solutions.
On the Nature of Opaque Cylindrical Regions Formed at Fibre Break Sites in a Fragmentation Test
Authors: Kislev T. , Marom G. , Berglund L. , Joffe R. , Nairn J.A. , Wagner H. D.
Published: January 2019

When a single-fibre composite test is performed to obtain information about the interfacial adhesion in a composite, a gradual strain increase often causes an opaque (black) cylinder to nucleate at, and grow from, the fibre failure sites. The nature of the opaque cylinder is difficult to ascertain using optical microscopy. This is the subject of the present note. To study the inside of the opaque cylinder we use several experimental methods based on imaging the failed region: optical microscopy, laser Raman spectroscopy and scanning electron microscopy. Mechanical models, including FEM analysis and analytic equations based on the shear-lag approach, are used to discuss the experimental work. The nature and growth mechanism of the opaque cylinder are of importance in defining the parameters and/or contributions that appear in both the force balance and the energy balance schemes.
Void Content and its Influence on the Fracture Behaviour of Long Fibre Reinforced Injection Molded Polypropylene
Authors: Rizov Victor Iliev
Published: January 2019

The influence of void content on the fracture performance of discontinuous long glass fibre reinforced injection molded polypropylene was studied. Compact tension specimens were machined from simple plate-tools and were loaded in a static testing machine in a laboratory environment. From the resulting load-displacement curves the fracture toughness was determined on the basis of the linear elastic fracture mechanics. It was found that higher void content causes a decrease in the fracture toughness.
Finite Element Simulation and Experimental Determination of Residual Stresses after Extrusion Process in Metal Matrix Composites
Authors: Albertini G. , Girardin E. , Giuliani A. , Ilie D.E. , O'Donnell B.P. , McGarry J.P. , McHugh P.E.
Published: January 2019

The introduction of reinforcement in a Metal Matrix causes micro-stresses which may prove to be very detrimental for the life of the component. Submitting the components to annealing thermal treatments introduces thermal mismatch stresses. They are generated during cooling due to the difference between the thermal expansion coefficient of the two phases. Finite Element Analysis has been performed to study this effect and the results have been experimentally validated by X-ray diffraction, SEM investigation and EDAX on an AA2009 + 25% SiCp extruded shaft for helicopters, simplified as a thin extruded tube.
Interface Characterization and Performance for the Development of Fibre-Reinforced Structural Composites
Authors: Matikas Theodore E.
Published: January 2019

The present work deals with the characterization of interfacial properties for the development and life prediction of metal matrix and ceramic matrix composites. Advanced non-destructive methods are developed for this endeavour. An innovative micro-mechanics parameter is introduced for evaluating the fibre/matrix interfacial shear stiffness. The interface elastic property both in metal matrix and ceramic matrix composites is determined using the shear-wave back reflectivity (SBR) ultrasonic technique. By means of this approach, the effect of residual radial stresses on the interfacial shear elastic property is quantified. In addition, the interface shear strength is determined in model metal matrix composites by in-situ monitoring of fibre fragmentation using an original ultrasonic technique for imaging fibre breaks of a few micrometers in width. Finally, the interfacial stress at fracture is evaluated in-situ in metal matrix composites using ultrasonic nondestructive monitoring of interfacial deformation and failure under incremental transverse loading of the fibre embedded in the matrix.
Stacking Sequence Effects on Natural Frequency of Laminated Composite Beams
Authors: Topcu Muzaffer , Atlıhaı Gökmen , Çallıoğlu Hasan , Çonkur E. Şahin
Published: January 2019

In this study, the natural frequencies of composite laminated beams are considered using experimental and theoretical approaches while the effects of stacking sequences of composite laminated beams on natural frequencies are investigated using theoretical approaches. A theoretical model of the laminated composite beam has been developed. Numeric calculations are carried out by means of a computer package program, ANSYS 7.0 that implements the finite element method (FEM). It has been concluded that in all of the modes considered, natural frequencies in the beam of angle (0°)12 are maximum values, natural frequencies in the beam composed of [(±52°)3]s are the lowest values according to the other stacking sequence and while natural frequencies in the beam of higher angles from [(±52°)3]s are getting higher, they at angle (90°)12 take more higher values. Furthermore, some of the results obtained from these theoretical analyses are compared with the experimental results using the composite laminated beam at [(0°/90°)3]s produced in Izoreel Composite Isolated Materials Company, Izmir, Turkey. Its natural frequencies are calculated both analytically and numerically. It has been concluded that experimental, theoretical and numerical results are very close to each other.
The Fracture Toughness of PVC / GRP Sandwich Systems in Marine Environment
Authors: Koçhan Cemal , Neşer Gökdeniz , Özes Çiçek
Published: January 2019

The aim of this study is to investigate experimentally the fracture toughness of sandwich systems with the PVC foam core in marine environment with a Mode-I Cracked Sandwich Beam (CSB) test arrangement. Five CSB specimens at each condition were tested. To get the values under marine environment, one set of specimen was conditioned in a 5% solution of NaCl for a 120 h period at a constant temperature of 50°C. It has been found that the fracture toughness of the PVC foam core material slightly increases under marine environmental conditions. It can be concluded that under the conditions in this study the system with the PVC core was largely unaffected by the immersion process.
Stress Analysis of Functionally Graded Isotropic Rotating Discs
Authors: Çallıoğlu Hasan
Published: January 2019

The closed-form study deals with stress analysis of annular rotating discs made of functionally graded materials (FGMs) subjected to internal and external pressures. The elasticity modulus and density of the discs are assumed to varies radially according to three diverse power law functions, and it is assumed that the material is of constant Poisson's ratio. A gradient parameter n is chosen between - 0.5 and 1.00. When n equals to zero, the disc becomes isotropic disc case. Dimensionless tangential and radial stresses and radial displacements in the rotating discs are depicted in the Fig. s and tabulated in a table. In present study, it is investigated how to change the distributions of the stresses and displacements with the increasing gradient parameter n (with variation of elasticity modulus and density). For a design problems if someone wants a disc which is of a homogenous stress distribution, he should chose either Disc 3 with n=1.00 or Disc 1 with n=-0.50 for the lowest stress distribution according to the results of this study for the material producer or applicability of production of the materials.
Some Studies about Machining of MMC's by MQL(Minimum Quantity of Lubricant) Conditions
Authors: Davim J. Paulo , Sreejith P. S. , Silva J.
Published: January 2019

The use of cutting fluids during machining operations is becoming problematic due to the environmental issues and employee health aspects. The use of cutting fluids is beneficial since it improves the tool life. The cutting fluids used for machining represents around 16 to 20% of the manufacturing costs; hence the extravagant use of cutting fluids may be restricted. But it should also be noted that some of the benefits of cutting fluids are not going to be available for dry machining and also dry machining will be acceptable only whenever the part quality and machining times achieved in wet machining are equalled or more. Hence the alternative is to machine with minimum quantity of lubricant (MQL). This paper deals with the machining of metal matrix composites (MMC) with MQL at different flow rates. It seen that MQL when properly applied will be able to give reasonable results in terms of cutting power, and surface finish.