bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the demarcation requirements of fish breeding and nursery sites to balance the exploitation, management and conservation needs of Lake Victoria ecosystem
Authors: Aura Christopher Mulanda , Nyamweya Chrisphine Sangara , Njiru James M. , Musa Safina , Ogari Zachary , May Linda , Wakwabi Enock
Published: September 2018

Fisheries resources in vital freshwater ecosystems have been reported to be under immense threat, resulting in conflicts between conservation, management and exploitation. This study established requirements for identifying and mapping fish breeding and nursery grounds in such ecosystems in the Kenyan part of Lake Victoria. The criteria were characterised by the use of indigenous knowledge, field data, literature on breeding sites, macroinvertebrates distribution, larval and relative fish abundances, digitisation, participatory mapping, and periodic sampling. Data were collected from trawl and seine net surveys. Digitisation and mapping of the proposed conservation sites were carried out using Quantum GIS software. Participatory physical demarcation of sites was done using buoys and markers. Larval and juvenile fishes were diverse and abundant in all seven river mouths and six bays surveyed with little variance; an important aspect of breeding areas. Additionally, a preponderance of macroinvertebrates and high fish diversity compared with offshore sites in the lake strengthened the hypothesis that these are critical habitats for spawning and preferred habitats for nurseries for fish. The approach can be adopted globally to guarantee the long‐term integrity of critical fish habitats for sustainable fisheries management and blue growth.
How to date natural archives of the Anthropocene
Authors: Waters Colin N. , Fairchild Ian J. , McCarthy Francine M.G. , Turney Chris S. M. , Zalasiewicz Jan , Williams Mark
Published: September 2018

The Anthropocene Epoch, as currently being formulated, is a little under 70 years old. Geologists who are used to defining geological time intervals in rocks that are many millions of years old now need to make use of very high‐resolution time signals, such as annual growth layers and geochemical or artefact markers, to characterize this proposed new Epoch.
The palaeontological record of the Anthropocene
Authors: Williams Mark , Zalasiewicz Jan , Waters Colin , Himson Stephen , Summerhayes Colin , Barnosky Anthony , Leinfelder Reinhold
Published: September 2018

Most species on planet Earth have specific ecological ranges. In the near surface of the oceans, planktonic foraminifera define water masses that are warm in the tropics, and cold in polar regions. Tropical rainforests have trees and animals that are distinct from those in warm temperate or cold temperate zones. The fauna and flora of Australia are distinct from those of the Americas. These natural patterns, defined by factors such as latitudinal changes in surface temperature and rainfall, or geographical isolation, have evolved over millions, sometimes tens of millions of years. Now this natural pattern is being overprinted by the actions of a single species, Homo sapiens, which has made the whole Earth its ecological range, and some parts of nearby space too. The human ancestral pattern of gradually increasing impact on the Earth can be traced in the stratigraphic record for nearly 3 million years, and in its later and more pervasive phases may serve to help define a biostratigraphical signal for the Anthropocene Epoch.
Flipped learning readiness in teaching programming in middle schools: Modelling its relation to various variables
Authors: Yildiz Durak Hatice
Published: September 2018

The aim of this study is to investigate the effect of students' flipped learning readiness (FLR) on engagement, programming self‐efficacy, attitude towards programming, and interaction intensity in the information and technology classrooms where programming is taught with the flipped classroom (FC) model. The study group of this research, which is designed by the relational screening method, consists of 371 students studying in middle school. Structural equation model was used for the data analysis. The results of the study revealed that FLR and its indicators in the programming teaching conducted with the FC model are significant predictors of engagement, attitude, programming self‐efficacy, and interaction intensity. FLR is most strongly related to programming self‐efficacy, whereas it is most weakly related to interaction. The most striking result of this study is that the FC model is an effective option in terms of providing engagement, interaction, self‐efficacy, and learner attitude, which are the key components for the success of the instruction. It is thought that this study assists to create an awareness on the impact of FLR on students, on subjects that frame in‐class attitudes, and behaviours of students.
Circular RNAs: Methodological challenges and perspectives in cardiovascular diseases
Authors: Carrara Matteo , Fuschi Paola , Ivan Cristina , Martelli Fabio
Published: September 2018

Circular RNAs are generated by back‐splicing of precursor‐mRNAs. Although they have been known for many years, only recently we have started to appreciate their widespread expression and their regulatory functions in a variety of biological processes. Not surprisingly, circular RNA dysregulation and participation in the pathogenic mechanisms have started to emerge in many instances, including cardiovascular diseases. Detection, differential expression analysis and validation are the three critical points for the characterization of any RNA, and circular RNAs are no exception. Their characteristics, however, generate several problems that are yet to be completely addressed, and literature still lacks comprehensive definitions of well‐defined best practices. We present a map of the current knowledge regarding circular RNAs and the critical issues limiting our understanding of their regulation and function. The goal was to provide the readers with the tools to critically decide which of the many approaches available is most suitable to their experimental plan. Although particularly focused on cardiovascular diseases, most critical issues concerning circular RNAs are common to many other fields of investigation.
Political Science and the Eurozone Crisis. A Review of Scientific Journal Articles 2004–15
Authors: Höing Oliver , Kunstein Tobias
Published: September 2018

We take a closer look at how political science engaged with Economic and Monetary Union (EMU) over a period of 12 years (2004–15). How intensively, and with what focus, have political science journals dealt with EMU? How has the scientific discourse on the topic changed with the outbreak of the global financial crisis, which led to a eurozone crisis?

Our systematic, qualitative analysis of articles (N=161) dealing with EMU in selected peer‐reviewed political science journals yields a number of interesting findings. First, we observe marked differences between the pre‐ and post‐crisis period. Specifically, political science has increasingly taken up issues of financial regulation and questions of trust in a monetary union. Second, political scientists did not engage as much as expected with the democratic ramifications of the crisis management. Finally, different crisis narratives persist, and none have been completely refuted.
Current status of the management of fall webworm, Hyphantria cunea: Towards the integrated pest management development
Authors: Edosa Tariku T. , Jo Yong H. , Keshavarz Maryam , Anh Young Sang , Noh Mi Young , Han Yeon S.
Published: September 2018

The fall‐webworm (FWW), Hyphantria cunea, is a highly polyphagous insect pest that is native to North America and distributed in different countries around the world. To manage this insect pest, various control methods have been independently evaluated in the invaded areas. Some of the control methods have been limited to the laboratory and need further study to verify their effectiveness in the field. On the other hand, currently, integrated pest management (IPM) has become a promising ecofriendly insect pest management option to reduce the adverse effect of insecticides on the environment. The development of an IPM for an insect pest must combine different management options in a compatible and applicable manner. In the native areas of the insect pests, there are some recommended management options. However, to date, there is no IPM for the management of the FWW in the newly invaded areas. Therefore, to develop an IPM for this insect pest, compilation of effective management option information is the first step. Thus, believing in the contribution of an IPM to the established management strategies, the chemical, biological, natural enemy, sex pheromone, and molecular studies regarding this insect were reviewed and potential future research areas were delineated in this review study. Therefore, using the currently existing management options, IPM development for this insect pest should be the subject of future research in the newly invaded areas.
Parameter uncertainty assessment of a flood forecasting model using multiple objectives
Authors: Pang Bo , Yue Jiajia , Huang Ziqian , Zhang Rong
Published: September 2018

The calibration of hydrological models used for flood forecasting is a difficult task that has received widespread attention. Assessing the uncertainty of flood forecasting models is fundamental to properly support decision‐making activities. Because of the demand of the different decision‐making objectives of a flood management system, we assess the uncertainty of flood forecasting models from a multiobjective perspective. Multicriteria decision analysis (MCDA) is adopted to evaluate the flood likelihood within a generalised likelihood uncertainty estimation (GLUE) framework. By combining four criteria representing different flood characteristics, the acceptability of the simulations is fully examined. The method is applied to an uncertainty analysis of a variable infiltration capacity model for the Xitiaoxi catchment. The results of 10,000 Monte Carlo simulations show that no single criterion can describe the characteristics of floods. Compared with two single‐criterion methods using the Nash–Sutcliffe efficiency, the multicriteria method shows advantages not only in assessing the prediction bounds but also in providing median GLUE estimates. The results indicate that a single criterion may be inadequate in parameter identification within the GLUE framework and that MCDA is an alternative approach to reduce the prediction uncertainty in flood forecasting.
Racial Differences in Cause‐Specific Mortality Between Community‐Dwelling Older Black and White Adults
Authors: Marron Megan M. , Ives Diane G. , Boudreau Robert M. , Harris Tamara B. , Newman Anne B.
Published: September 2018

Objectives

To understand which causes of death are higher in black than white community‐dwelling older adults and determine whether differences in baseline risk factors explain racial differences in mortality.

Design

Longitudinal cohort study (Health, Aging, and Body Composition Study).

Setting

Pittsburgh, Pennsylvania; and Memphis, Tennessee.

Participants

Black and white men and women aged 70 to 79 during recruitment (N=3,075; 48% men, 42% black) followed for a median of 13 years.

Measurements

A committee of physicians adjudicated cause of death, which was categorized as cardiovascular disease (CVD), stroke, cancer, dementia, pulmonary, infection, kidney, or other causes. Using competing risks regression, we examined whether known risk factors at baseline (demographic characteristics, smoking, body mass index, chronic diseases, physical function, cognition) could explain racial differences in cause‐specific mortality risk.

Results

During follow‐up, 1,991 (65%) participants died. Black participants died at higher rates from cancer (hazard ratio (HR)=1.36, 95% confidence interval (CI)=1.14–1.63), kidney disease (HR=2.09, 95% CI=1.16–3.74), stroke (HR=1.31, 95% CI=0.98–1.76); and CVD (HR=1.16, 95% CI=0.98–1.37). Poorer physical and cognitive performance at baseline among black participants explained most of the racial difference in risks of dying from kidney disease, stroke, and CVD but not cancer. When examining types of cancer deaths, black participants died at higher rates from multiple myeloma, pancreatic cancer, and prostate cancer, which baseline risk factors did not explain either.

Conclusion

Factors contributing to poorer physical and cognitive performance in similarly aged black men and women could be targets to reduce excess mortality from CVD, stroke, and kidney disease. More work is needed to identify factors contributing to cancer mortality disparities.
Studying the sensory ecology of frog‐biting midges (Corethrellidae: Diptera) and their frog hosts using ecological interaction networks
Authors: Grafe T. U. , Ahmad Sah H. H. , Ahmad N. , Borkent A. , Meuche I. , Konopik O.
Published: September 2018

Investigating species interaction networks has advanced the understanding of the robustness of ecosystems, the impact of species invasions, resource partitioning and the coevolution of interacting species. Here, we present a 10‐year study of the relationships between frog‐biting midges (Corethrella) and their frog hosts in tropical lowland forests across northern Borneo. We use quantitative bipartite host‐ectoparasite networks to explore this unusual relationship. Across northern Borneo, nine species of frog‐biting midges were found to bite 29 species of frogs. Overall, 378 individual Corethrella were found on 93 individual frogs. We compare the network structure between two forest types in Brunei Darussalam: a lowland mixed‐dipterocarp rainforest and a peatswamp forest. Results indicate that both antagonistic interaction networks were relatively specialized at the community level and show significant nestedness. The degree of specialization was higher in the rainforest than in the peatswamp suggesting higher diversity of midge sensory perception and frog avoidance strategies in the rainforest. At the species level, the specialization of midges as well as their frog hosts was highly variable in both networks suggesting that some frog species are better at avoiding being bitten by Corethrella than others. Frog species parasitized by midges had calls of low dominant frequencies suggesting that the spectral bandwidth of hearing in midges could influence host selection. Despite this, some frog species that call above 4 kHz have not escaped parasitism. We explore the role of habitat filtering, behavior and coevolution in shaping network structure.
van Manen's phenomenology of practice: How can it contribute to nursing?
Authors: Errasti‐Ibarrondo Begoña , Jordán José Antonio , Díez‐Del‐Corral Mercedes P. , Arantzamendi María
Published: September 2018

Phenomenology of practice is a useful, rigorous way of deeply understanding human phenomena. Therefore, it allows research to be conducted into nursing's most sensitive and decisive aspects. While it is a widely used research approach and methodology in nursing, it is seldom addressed and made use of in its practical and applied value. This article aimed to approach the global outlook of van Manen's hermeneutic‐phenomenological method to better understand its theoretical background and to address and support the contribution this method can make to nursing, if rigorously applied. For a professional discipline like nursing, van Manen's approach is especially interesting because, in addition to contributing to the body of knowledge of nursing, it provides a special kind of knowledge that allows nurses to act in a more reflective manner, and with tact and skill, in certain situations and relationships that arise in their daily practice. A more in‐depth understanding of this research methodology may help nurse‐researchers make good use of it and also harness knowledge derived from this type of research. This comes as a result of assuming that phenomenological texts, the final product of the research, have tremendous educational potential for people who read them carefully.
Budgetary Balances Adjustments From Governmental Accounting to National Accounts in EU Countries: Can Deficits Be Prone to Management?
Authors: Jorge Susana , Jesus Maria Antónia , Laureano Raul
Published: September 2018

European Union (EU) countries are required to achieve deficit targets and are thus incentivized to use tools to keep within budgetary limits. This paper argues that accounting discretion might be used to manage some adjustments made during the translation of data from Governmental Accounting (GA) into National Accounts (NA), to window‐dress the final deficit/surplus reported to EUROSTAT. The empirical research shows there are certain circumstances that might facilitate the use of GA–NA “adjustment discretion.” EU authorities must pay special attention to these conditions to ensure the reliability of reported deficits. The main findings of this paper could also assist in future efforts to improve the integrity of the adjustment process.
When the Big One Came: A Natural Experiment on Demand Shock and Market Structure in India's Influenza Vaccine Markets
Authors: Adbi Arzi , Chatterjee Chirantan , Drev Matej , Mishra Anant
Published: September 2018

This study examines the relationship between exogenous demand shock and market structure in India's influenza vaccine markets. Using a novel dataset of detailed purchasing information for vaccines in India, and exploiting the 2009–10 global H1N1 pandemic as an exogenous demand shock, we provide evidence of heterogeneous responses to the shock by domestic and multinational vaccine manufacturers in the influenza vaccine market relative to our control group of all other vaccine markets. We find that such a shock results in a reversal of the market structure for influenza vaccines in India, with a decline in the market share of multinational vaccine manufacturers and significant gains in the market share of domestic vaccine manufacturers. This reversal of the market structure is driven by increased efforts at new product introduction among domestic vaccine manufacturers, the effects of which persist even after the pandemic has ended. Our results remain robust to the use of alternative controls, synthetic control method, coarsened exact matching method, and other relevant estimation methodologies. These results provide new evidence on the role of a pandemic‐induced demand shock in the context of an emerging economy by creating differential incentives for domestic and multinational vaccine manufacturers to bring new products to market. We also conduct additional analysis to explore the impact of targeted policy instruments on the new product introduction efforts of domestic vaccine manufacturers. Finally, we discuss the implications of our findings and offer insights into the role of policy on pandemic preparedness in emerging markets facing adverse welfare effects from pandemics.
Early Illicit Drug Use and The Age of Onset of Homelessness
Authors: McVicar Duncan , Moschion Julie , Ours Jan C.
Published: September 2018

We investigate the effect of taking up daily use of cannabis on the onset of homelessness by using Australian data. We use a bivariate simultaneous mixed proportional hazard model to address potential biases due to common unobservable factors and reverse causality. We find that taking up daily use of cannabis substantially increases the probability of transitioning into homelessness for young men but not young women. In contrast, the onset of homelessness increases the probability of taking up daily use of cannabis for young women but not for young men. In a trivariate extension we find that the use of other illicit drugs at least weekly has no additional effect on transitions into homelessness for either gender but there is a large if imprecisely estimated effect of onset of homelessness on taking up weekly use of such drugs for young women.
The European flexicurity concept and the Dutch and Danish flexicurity models: How have they managed the Great Recession?
Authors: Bekker Sonja , Mailand Mikkel
Published: September 2018

In the mid‐2000s, the flexicurity concept was developed into a key EU policy concept. It drew its inspiration from the Danish and Dutch practices to combine labor market flexibility and security. However, the crisis' focus on bringing down national deficits and debts left little room to advance the concept. Lately, more emphasis has been placed on the need to take into consideration the social aspect of economic policy‐making. Current EU level documents see flexicurity as a guidance for structural reforms. However, the European flexicurity initiatives seem never to have had much impact in Denmark and the Netherlands. There are few accounts of the recent adjustment to the flexicurity models, be it at the EU or at national levels. Therefore, this article assesses the fate of flexicurity by scrutinizing its (adjusted) use as a political concept as well as a socio‐economic model. Although the Danish flexicurity model resembles the European flexicurity concept to a large extent, recent reforms have, overall, weakened rather than strengthened the flexicurity model. The Dutch flexicurity model has a narrower focus on normalizing atypical work, while recent reforms support this narrow flexicurity model. Meanwhile, the EU level concept has been changing every year, encompassing a growing number of issues.
ADAMTS13: origins, applications, and prospects
Authors: Plautz William E. , Raval Jay S. , Dyer Mitchell R. , Rollins‐Raval Marian A. , Zuckerbraun Brian S. , Neal Matthew D.
Published: September 2018

ADAMTS13 is an enzyme that acts by cleaving prothrombotic von Willebrand factor (VWF) multimers from the vasculature in a highly regulated manner. In pathologic states such as thrombotic thrombocytopenic purpura (TTP) and other thrombotic microangiopathies (TMAs), VWF can bind to the endothelium and form large multimers. As the anchored VWF chains grow, they provide a greater surface area to bind circulating platelets (PLTs), generating unique thrombi that characterize TTP. This results in microvasculature thrombosis, obstruction of blood flow, and ultimately end‐organ damage. Initial presentations of TTP usually occur in an acute manner, typically developing due to an autoimmune response toward, or less commonly a congenital deficiency of, ADAMTS13. Triggers for TMAs that can be associated with ADAMTS13 deficiency, including TTP, have been linked to events that place a burden on hemostatic regulation, such as major trauma and pregnancy. The treatment plan for cases of suspected TTP consists of emergent therapeutic plasma exchange that is continued on a daily basis until normalization of PLT counts. However, a subset of these patients does not respond favorably to standard therapies. These patients necessitate a better understanding of their diseases for the advancement of future therapeutic options. Given ADAMTS13’s key role in the cleavage of VWF and the prevention of PLT‐rich thrombi within the microvasculature, future treatments may include anti‐VWF therapeutics, recombinant ADAMTS13 infusions, and ADAMTS13 expression via gene therapy.
Analysis of red blood cell use in elective surgeries over 12 years in Korea
Authors: Kim Banseok , Park Yongjung , Kim Young Ah , Kang Minjin , Kim Sinyoung , Kim Hyun Ok
Published: September 2018

BACKGROUND

Red blood cell (RBC) transfusion is a lifesaving process for patients with perioperative bleeding, but transfusion can cause adverse events. Effective utilization and management of blood products as a limited resource is essential when considering cost‐efficiency and patient safety.

STUDY DESIGN AND METHODS

We analyzed the number of RBC units used during the hospitalization of patients who had undergone surgical procedures from 2002 to 2013 using National Health Insurance Service‐National Sample Cohort data, which include a total of 487,238 cases for 206 selected operations.

RESULTS

RBC units were used in 39,637 (8.1%) cases. A total of 60,815 RBC units were transfused with a mean of 0.13 units per patient overall and a mean of 1.53 units per case receiving RBC transfusion. In addition, 56.7% of the RBC units were transfused for females, and 60.1% of RBC units were transfused into patients aged 60 or older. RBC units were used most often in orthopedic surgeries (33.8%), followed by general surgeries (12.0%) and vascular surgeries (11.8%). The number of operations performed in the cohort increased from 27,690 in 2002 to 49,473 in 2013, and the mean number of RBC units used per operation also increased from 0.08 units in 2002 to 0.15 units in 2013.

CONCLUSION

Continuous management for blood preparation and transfusion is needed for efficient utilization of blood. Periodic investigation on the use of blood products through nationwide studies could suggest data applicable to blood product preparation for various elective surgical operations.
Firm heterogeneity and aggregate business services exports: Micro evidence from Belgium, France, Germany and Spain
Authors: Ariu Andrea , Biewen Elena , Blank Sven , Gaulier Guillaume , González María Jesus , Meinen Philipp , Mirza Daniel , Martín Cesar , Tello Patry
Published: September 2018

This paper uses detailed micro data on services exports at the firm–destination–service level to analyse the role of firm heterogeneity in shaping aggregate services exports in Belgium, France, Germany and Spain from 2003 to 2007. We decompose the level and the growth of aggregate services exports into different trade margins paying special attention to firm heterogeneity within countries. We find that the weak export growth of France is at least partly due to poor performance by small exporters. By contrast, small exporters are the most dynamic contributors to the aggregate exports of Belgium, Germany and Spain. Our results highlight the importance of firm heterogeneity in understanding aggregate export growth.
Immune role of platelets in malaria
Authors: McMorran Brendan J.
Published: September 2018

Plasmodium infections causing malaria threaten over 3 billion people from more than ninety countries. Despite control efforts spanning several decades, there are still more than 400,000 fatalities annually. Survival to malaria is largely determined by the host response mounted against the parasite, and the ensuing balance of inflammatory, tissue‐damaging reactions and immune‐mediated mechanisms directed towards controlling pathogen growth. Platelets appear to play important roles in each of these processes. On one hand, platelets have been implicated adversely in cerebral malaria, a severe disease manifestation where microvascular occlusions develop in the brain, leading to inflammatory foci and brain swelling, and causing coma and often death. Platelets adhere to the cerebral endothelium and mediate accumulation of infected erythrocytes in the brain, with the postulated outcome of increasing severity or of even mediating this disease. On the other hand, platelets can directly kill parasites in the periphery by binding to infected red cells and thereby contribute to the host's ability to control the infection. Platelet binding to infected red cells releases an antimicrobial protein, platelet factor 4 (PF4), which accumulates inside the cell and kills the parasite by lysing the food vacuole. The Duffy antigen, a red cell‐expressed receptor of PF4, is required for the PF4 accumulation and parasite killing. Further understanding of the roles of platelets in malaria, especially in clinical disease, is required. This knowledge may provide novel interventions and therapeutic tools, which are so desperately needed.
The effects of climate warming and urbanised areas on the future distribution of Cortaderia selloana, pampas grass, in France
Authors: Tarabon S , Bertrand R , Lavoie C , Vigouroux T , Isselin‐Nondedeu F
Published: September 2018

The spread of many invasive plants could be facilitated by their presence in urban areas that may act as dispersal centres and by climate warming. Cortaderia selloana, pampas grass, is native to South America and raises considerable concern worldwide as an introduction. We used Maxent niche modelling, based on occurrence records and on a set of simulated occurrence points with high probability of presence in urbanised areas in France, where the species was introduced and is still planted. We calibrated the model with current climate data coupled with several habitat variables and used it to predict range shifts of C. selloana under four climate change scenarios (RCP) for 2060. The results were consistent with the known ecology of the species and showed that the most important variables that explain the current distribution in the introduced area were mean annual minimum temperatures, sandy habitats, disturbed habitats and urbanised areas. While the species already occupies large areas along the western and Mediterranean coasts, the models predicted an expansion northward and inland to the east under future climates. The area of suitable habitats could increase by up to 69% under the RCP 8.5 climate scenario in 2060 and by 116% with the extra occurrences in urban/suburban areas. This latter scenario suggests that areas like public and private gardens or urban parks, where the species is currently cultivated, could contribute to increase the invasion risk under climate warming. The results provide predictions of potential environments for the species, which can be helpful for anticipating its spread.
Transformational Leadership and Job Satisfaction: The Case of Secondary Education Teachers in Greece
Authors: Kouni Zacharo , Koutsoukos Marios , Panta Dimitra
Published: September 2018

In international literature there are many documented studies which have shown the relationship between leadership and job satisfaction. Specifically, transformational leadership is highly associated with this important and positive work attitude, that is, job satisfaction. The interpretation in a school context is that the director should operate as transformational leader so as to produce better educational outcomes through teachers' job satisfaction. In Greece, little empirical research has been done to investigate the perceptions of teachers about the relationship between transformational leadership and job satisfaction of teachers. The purpose of the present study is to investigate the perceptions of teachers to the extent that transformational leadership contributes to job satisfaction. The selected research method is a combination of quantitative and qualitative methods, namely using the questionnaire and the interview. The sample consisted of 171 teachers from two types of educational institutions, secondary junior high schools and high schools, of a local directorate of secondary education. The survey results showed that teachers feel substantial satisfaction when the school principal acts as a transformational leader. Demographic variables, the type of school, and work experience, do not affect the views of teachers.
Examining University Students’ Self-Compassion and Compassionate Love Levels in Terms of Perceived Parental Attitudes
Authors: Eker Halime , Kaya Mehmet
Published: September 2018

The aim of this research is to investigate the relationship between parental attitudes perceived by the students, self-compassion and compassionate love levels, and differences occur in parental attitudes, self-compassion and compassionate love levels according to various variables. The research was conducted with 326 university students studying in different departments of Sakarya University Faculty of Education. Parental Attitude Scale (PAS), Self-Compassion Scale (SCS), the Compassionate Love Scale (CLS) and Information Collection Form were applied in the study. The research data were analyzed by correlation, T-test and One Way (ANOVA). The results of the research revealed that the self-compassion level of the students who perceived the parents' attitudes as democratic was high, whereas the self-compassion level of the students who perceived the parental attitudes as authoritarian and protective-demanding was low. It was also found out that the students who perceived their parents' attitudes as authoritarian and protective-demanding had high compassionate love levels.  The present study demonstrated the authoritarian and protective-demanding parental attitudes perceived by university students differed according to sex, the democratic parental attitude differed in terms of the number of siblings, and the compassionate love differed in terms of gender. It was revealed that there was a negative relationship between self-compassion and compassionate love.
Magnetohydrodynamics,
Natural Convection, and Entropy Generation of CuO–Water Nanofluid in an I-Shape Enclosure—A
Numerical Study
Authors: Malekpour Ali , Karimi Nader , Mehdizadeh Amirfarhang
Published: September 2018

This paper presents a numerical study of the magnetohydrodynamics, natural convection, and thermodynamic irreversibilities in an I-shape enclosure, filled with CuO-water nanofluid and subject to a uniform magnetic field. The lateral walls of the enclosure are maintained at different but constant temperatures, while the top and bottom surfaces are adiabatic. The Brownian motion of the nanoparticles is taken into account and an extensive parametric study is conducted. This involves the variation of Rayleigh and Hartmann numbers, and the concentration of nanoparticles and also the geometrical specifications of the enclosure. Further, the behaviors of streamlines and isotherms under varying parameters are visualized. Unlike that in other configurations, the rate of heat transfer in the I-shaped enclosure appears to be highly location dependent and convection from particular surfaces dominates the heat transfer process. It is shown that interactions between the magnetic field and natural convection currents in the investigated enclosure can lead to some peculiarities in the thermal behavior of the system. The results also demonstrate that different parts of the enclosure may feature significantly different levels of heat transfer sensitivity to the applied magnetic field. Further, the analysis of entropy generation indicates that the irreversibility of the system is a strong function of the geometrical parameters and that the variations in these parameters can minimize the total generation of entropy. This study clearly shows that ignoring the exact shape of the enclosure may result in major errors in the prediction of heat transfer and second law performances of the system.
Effects of Novel Collector Roof on Solar Chimney Power Plant Performance
Authors: Elwekeel Fifi N. M. , Abdala Antar M. M. , Rahman Muhammad Mustafizur
Published: September 2018

The effects of collector roughness shape on the performance of solar chimney power plant were investigated in this study. The roughness shapes of triangular, curved, and square grooves were chosen and were compared to smooth case. The performance parameters of solar radiation, updraft velocity, temperature distribution, static pressure, power, and Nusselt number were varied. The effects of number, position, height, and width of the grooves on the performance were investigated. The results of this investigation show that the updraft velocity with the triangular groove increases by 1.5 times compared to the smooth case at solar radiation of 1000 W/m2. At solar radiation of 1000 W/m2, the power increases by 169%, 96%, and 19% for triangular, curved, and square grooves, respectively, compared to the smooth case. Moreover, the Nusselt number values with triangular groove and curved groove enhance by 42% and 26%, respectively, compared to the smooth case. The power increases by 1.98% for three grooves instead of using one groove at higher solar radiation. Increasing the groove height by 1.7 times, the power increases by 1.03 times at higher solar radiation. The power enhancement shows less sensitivity to the change of groove width at higher solar radiation.
Experimental Study of Laminar Burning Speed for Premixed Biomass/Air Flame
Authors: Bai Ziwei , Wang Ziyu , Yu Guangying , Yang Yongping , Metghalchi Hameed
Published: September 2018

Biomass has been considered as a valuable alternative fuel recently. A fundamental property of biomass/air flame, laminar burning speed, is measured in this research. Experiments have been made in a cylindrical combustion vessel with two end windows. Central ignition has been used to start the combustion process. A high-speed CMOS camera capable of taking pictures of 40,000 frames per second has been used to study morphology of flame front. Flames are initially smooth, and as pressure and flame radius increase, cracks and cells appear on the flame surface. In this paper, experimental results have only been reported for smooth flames. A multishell thermodynamic model to measure laminar burning speed of biomass/air mixture with varying CO2 concentrations (0%–60%), based on the pressure rise data collected from a cylindrical chamber during combustion, has been developed in this paper. Burning speed has been only reported for flame radii larger than 4 cm in radius in order to have negligible stretch effect. Power law correlations, to predict burning speed of biomass/air mixtures, based on the measured burning speeds, have been developed for a range of temperatures of 300–661 K, pressures of 0.5–6.9 atmospheres, equivalence ratios of 0.8–1.2, and CO2 concentrations 0%–60%. Moreover, the measured laminar burning speeds have been compared with simulation results using a one-dimensional steady-state laminar premixed flame program with GRI-Mech 3.0 mechanism and other available data from literatures. Comparison with existing data has been excellent.
Surface Variation Modeling by Fusing Multiresolution Spatially Nonstationary Data Under a Transfer Learning Framework
Authors: Ren Jie , Wang Hui
Published: September 2018

High-definition metrology (HDM) has gained significant attention for surface quality inspection since it can reveal spatial surface variations in detail. Due to its cost and durability, such HDM measurements are occasionally implemented. The limitation creates a new research opportunity to improve surface variation characterization by fusing the insights gained from limited HDM data with widely available low-resolution surface data during quality inspections. A useful insight from state-of-the-art research using HDM is the revealed relationship and positive correlation between surface height and certain measurable covariates, such as material removal rate (MRR). Such a relationship was assumed spatially constant and integrated with surface measurements to improve surface quality modeling. However, this method encounters challenges when the covariates have nonstationary relationships with the surface height over different surface areas, i.e., the covariate-surface height relationship is spatially varying. Additionally, the nonstationary relationship can only be captured by HDM, adding to the challenge of surface modeling when most training data are measured at low resolution. This paper proposes a transfer learning (TL) framework to deal with these challenges by which the common information from a spatial model of an HDM-measured surface is transferred to a new surface where only low-resolution data are available. Under this framework, the paper develops and compares three surface models to characterize the nonstationary relationship including two varying coefficient-based spatial models and an inference rule-based spatial model. Real-world case studies were conducted to demonstrate the proposed methods for improving surface modeling.
Stability Prediction Based Effect Analysis of Tool Orientation on Machining Efficiency for Five-Axis Bull-Nose End Milling
Authors: Tang Xiaowei , Zhu Zerun , Yan Rong , Chen Chen , Peng Fangyu , Zhang Mingkai , Li Yuting
Published: September 2018

The traditional stability analysis by only considering cutting depth-spindle speed lobe diagram is appropriate for parameters optimization and efficiency improvement of the five-axis ball-end milling. However due to the complicated cutter-workpiece engagement (CWE) of bull-nose end cutter in five-axis milling, the maximal cutting depth may not produce the maximal material removal rate (MRR). Thus, the traditional stability analysis is not suitable for the five-axis bull-nose end milling in parameters optimization, and this paper presents a new stability analysis method to analyze the effect of tool orientation on machining efficiency for five-axis bull-nose end milling. In the establishing of stability prediction model, coordinate transformation and vector projection method are adopted to identify the CWE and dynamic cutting thickness, and the geometrical relationship of frequency response function (FRF) coordinate system and cutting force coordinate system with variable tool orientation is derived to establish the conversion of FRF and cutting force in stability equation. Based on the CWE sweeping, the cutting area along the feed direction is calculated to realize the critical MRR analysis in the stability model. Based on the established stability prediction model, the effects of tool orientation on critical cutting depth and MRR considering the chatter constraint are analyzed and validated by the cutting experiments, respectively. The lead-tilt diagram, which not only gives the boundary of stability region but also describes the contour line for MRR, is proposed for the further tool orientation optimization.
Spring-Assisted Motorized Transmission for Efficient Hover by Four Flapping Wings
Authors: Chin Yao-Wei , Ang Ziyuan , Luo Yukai , Chan Woei-Leong , Chahl Javaan S. , Lau Gih-Keong
Published: September 2018

Elastic storage has been reported to help flying insects save inertial power when flapping their wings. This motivates recent research and development of elastic storage for flapping-wing micro air vehicles (fwMAVs) and their ground (tethered) flight tests. The previous designs of spring-loaded transmissions are relatively heavy or bulky; they have not yet been adopted by freely hovering prototypes of fwMAVs, especially those with four flapping wings. It is not clear if partial elastic storage can still help save power for flapping flight while not overloading the motorized transmission. Here, we developed ultralight and compact film hinges as elastic storage for four flapping wings. This spring-assisted transmission was motor driven such that the wing beat frequency was higher than the natural frequency of elastically hinged wings. Our experiments show that spring recoil helps accelerate wing closing thus generating more thrust. When powered by a 3.18 g brushless motor, this 13.4 g fwMAV prototype with spring-assisted transmission can take off by beating four flexible wings (of 240 mm span) with up to 21–22 g thrust generation at 22–23 Hz. Due to lower disk loading and high-speed reduction, indirect drive of the four elastically hinged wings can produce a thrust per unit of electrical power of up to 4.6 g/W. This electrical-power-specific thrust is comparable to that generated by direct drive of a propeller, which was recommended by the motor (AP-03 7000kv) manufacturer.
A Fixed Structure Gain Selection Strategy for High Impedance Series Elastic Actuator Behavior
Authors: Isik Kenan , Thomas Gray Cortright , Sentis Luis
Published: September 2018

Series elastic actuators (SEA) are widely used for impact protection and compliant behavior, but they typically fall short in tasks calling for accurate position control. In this paper, we propose a simple and effective heuristic for tuning series elastic actuator controllers to a high impedance position control behavior, which compares favorably with previous publications. Our approach considers two models, an ideal model and a nonideal model with time delays and filtering lag. The ideal model is used to design cascaded proportional-derivative (PD)-type outer impedance and inner force loops as a function of critically damped closed-loop poles for the force and impedance loops. The nonideal model provides an estimate of the phase margin of the position controller for each candidate controller design. A simple optimization algorithm finds the best high-impedance behavior for which the nonideal model meets a desired phase margin requirement. In this way, the approach automates the trade-off between force and impedance bandwidth. The effect of important system parameters on the impedance bandwidth is also analyzed and the proposed method verified with a physical actuator.
Effect of Unbalance Force Vector Orientation on the Whirl Response of Cracked Rotors
Authors: AL-Shudeifat Mohammad A. , Al Hosani Hanan , Saeed Adnan S. , Balawi Shadi
Published: September 2018

The combined effect of a crack with unbalanced force vector orientation in cracked rotor-bearing-disk systems on the values and locations of critical whirl amplitudes is numerically and experimentally investigated here for starting up operations. The time-periodic equations of motion of the cracked system are formulated according to the finite element (FE) time-varying stiffness matrix. The whirl response during the passage through the critical whirl speed zone is obtained via numerical simulation for different angles of the unbalance force vector. It is found that the variations in the angle of unbalance force vector with respect to the crack opening direction significantly alters the peak values of the critical whirl amplitudes and their corresponding critical whirl speeds. Consequently, the critical speeds of the cracked rotor are found to be either shifted to higher or lower values depending on the unbalance force vector orientation. In addition, the peak whirl amplitudes are found to exhibit significant elevation in some zones of unbalance force angles whereas significant reduction is observed in the remaining zones compared with the crack-free case. One of the important findings is that there exists a specific value of the unbalance force angle at which the critical whirl vibration is nearly eliminated in the cracked system compared with the crack-free case. These all significant numerical and experimental observations can be employed for crack damage detection in rotor systems.
Clear speech adaptations in spontaneous speech produced by young and older adults
Authors: Hazan Valerie , Tuomainen Outi , Kim Jeesun , Davis Christopher , Sheffield Benjamin , Brungart Douglas
Published: September 2018

The study investigated the speech adaptations by older adults (OA) with and without age-related hearing loss made to communicate effectively in challenging communicative conditions. Acoustic analyses were carried out on spontaneous speech produced during a problem-solving task (diapix) carried out by talker pairs in different listening conditions. There were 83 talkers of Southern British English. Fifty-seven talkers were OAs aged 65–84, 30 older adults with normal hearing (OANH), and 27 older adults with hearing loss (OAHL) [mean pure tone average (PTA) 0.250–4 kHz: 27.7 dB HL]. Twenty-six talkers were younger adults (YA) aged 18–26 with normal hearing. Participants were recorded while completing the diapix task with a conversational partner (YA of the same sex) when (a) both talkers heard normally (NORM), (b) the partner had a simulated hearing loss, and (c) both talkers heard babble noise. Irrespective of hearing status, there were age-related differences in some acoustic characteristics of YA and OA speech produced in NORM, most likely linked to physiological factors. In challenging conditions, while OANH talkers typically patterned with YA talkers, OAHL talkers made adaptations more consistent with an increase in vocal effort. The study suggests that even mild presbycusis in healthy OAs can affect the speech adaptations made to maintain effective communication.