bluuebunny/crossref_metadata_2025 huggingface dataset:
Interfacial Morphology between Ramie Fibers and Phenolic Resins: Effects of Plasma Treatment and Cure Cycle
Authors: Hamad Sameer F , Fei Teng , Hayes Simon A , Foreman Joel P , Rodenburg Cornelia
Published: January 2022

Natural fiber–reinforced polymer composites offer many advantages over conventional composite materials, such as availability, low cost, inexpensive, lightweight, and high specific mechanical properties. However, the applications of these materials are still limited due to the challenges in achieving a good interface between the fibers and matrix. This is highly influenced by the fiber surface characteristics and the polymer matrix properties. Therefore, in this study, the surface characteristics of ramie fibers were modified using low-pressure plasma treatment in order to improve their interface to the phenolic resin. Furthermore, the effects of using two different curing cycles (acid cure and thermal cure) on the properties of short ramie fiber-phenolic composites were also investigated. A new method for making mats of random short ramie fibers was developed and used for the fabrication of composites containing plasma-treated fibers. The flexural properties of all composites were tested and the obtained fracture surfaces were investigated using LV-SEM. The results indicate that both plasma treatment and cure cycle conditions influence the fiber–matrix interface and consequently the flexural properties of the composites.
Low-velocity and ballistic impact resistances of particle reinforced metal–matrix composites: An experimental study
Authors: Kosedag Ertan , Ekici Recep
Published: January 2022

This study investigates the low-velocity and ballistic impact responses of SiC-reinforced Al6061 metal–matrix composites in different reinforcement volume fractions. Low-velocity impact (LVI) tests were performed with samples having SiC particle volume fractions of 0, 5, 10, 15, 20, 30, and 40%, while ballistic tests were carried out with samples having volume fractions of 0, 10, 20, and 30%. The weight-drop test method was used for LVI by applying 50 J (4.45 m/s) energy to all samples. Ballistic tests were carried out under the same conditions on all samples with the projectile launched at an average velocity of 500 m/s. For the determination of the ballistic resistance of the samples, the projectile penetrations in the witness structures were taken into consideration. The damage and deformations caused by both the LVI and the ballistic test in composites were examined. By the LVI test results, composite samples have absorbed less impact energy by increasing the reinforcement volume fraction, as well as demonstrated superior performance compared to unreinforced samples. In addition, the crack formation was mainly observed in the samples containing 30% reinforcement, while the composite material with a 40% volume fraction was completely broken. With the increase in the reinforcement volume fraction, the ballistic resistance of the samples increased significantly.
Dark Triad Traits, Social Position, and Personality: A Cross-Cultural Study
Authors: Aluja Anton , García Luis. F. , Rossier Jérôme , Ostendorf Fritz , Glicksohn Joseph , Oumar Barry , Bellaj Tarek , Ruch Willibald , Wang Wei , Suranyi Zsuzsanna , Ścigała Dawid , Čekrlija Đorđe , Stivers Adam W. , Blas Lisa Di , Valdivia Mauricio , Ben Jemaa Sonia , Atitsogbe Kokou A. , Hansenne Michel
Published: January 2022

This research explores the Dark Triad traits in 18 cultures from Europe, America, Africa, and Asia. We examined the relationships among Dark Triad traits, as measured by the SD3, with gender, age, social status, and two personality models, HEXACO and Zuckerman’s alternative five factor model (AFFM). There were 10,298 participants (5,410 women and 4,888 men) with a mean age of 40.31 ( SD = 17.32) years old. Between 6% and 16% of the variance in the Dark Triad traits was accounted by culture. Men scored higher than women on all three traits in most cultures, but gender differences were generally larger in European countries. The relationship between the Dark Triad traits dimensions and age is negative, but the largest effect size is small (Psychopathy; η2 = .018). Psychopathy is associated with low Social Position, and Narcissism with high Social Position. In regard to Personality traits, Narcissism is positively related to Extraversion, and Psychopathy is negatively related to Conscientiousness for the HEXACO, and Narcissism is positively related to Activity and Sensation Seeking, and Machiavellianism and Psychopathy are positively related to Aggressiveness and Sensation Seeking for the AFFM.
Pathways Linking Oral Bacteria, Nitric Oxide Metabolism, and Health
Authors: Morou-Bermúdez E. , Torres-Colón J.E. , Bermúdez N.S. , Patel R.P. , Joshipura K.J.
Published: January 2022

Nitrate-reducing oral bacteria have gained a lot of interest due to their involvement in nitric oxide (NO) synthesis and its important cardiometabolic outcomes. Consortia of nitrate-metabolizing oral bacteria associated with cardiometabolic health and cognitive function have been recently identified. Longitudinal studies and clinical trials have shown that chronic mouthwash use is associated with increased blood pressure and increased risk for prediabetes/diabetes and hypertension. Concurrently, recent studies are beginning to shed some light on the complexity of nitrate reduction pathways of oral bacteria, such as dissimilatory nitrate reduction to ammonium (DNRA), which converts nitrite into ammonium, and denitrification, which converts nitrite to NO, nitrous oxide, and dinitrogen. These pathways can affect the composition and metabolism of the oral microbiome; consequently, salivary nitrate and nitrite metabolism have been proposed as targets for probiotics and oral health. These pathways could also affect systemic NO levels because NO generated through denitrification can be oxidized back to nitrite in the saliva, thus facilitating flux along the NO3–-NO2–-NO pathway, while DNRA converts nitrite to ammonium, leading to reduced NO. It is, therefore, important to understand which pathway predominates under different oral environmental conditions, since the clinical consequences could be different for oral and systemic health. Recent studies show that oral hygiene measures such as tongue cleaning and dietary nitrate are likely to favor denitrifying bacteria such as Neisseria, which are linked with better cardiometabolic health. A vast body of literature demonstrates that redox potential, carbon-to-nitrate ratio, and nitrate-to-nitrite ratio are key environmental drivers of the competing denitrification and DNRA pathways in various natural and artificial ecosystems. Based on this information, a novel behavioral and microbial model for nitric oxide metabolism and health is proposed, which links lifestyle factors with oral and systemic health through NO metabolism.
Single Leg Balance Training: A Systematic Review
Authors: Marcori Alexandre J , Monteiro Pedro H M , Oliveira Júlia A , Doumas Michail , Teixeira Luis A
Published: January 2022

Single leg balance training promotes significant increments in balance control, but previous reviews on balance control have not analyzed this form of balance training. Accordingly, we aimed to review the single leg balance training literature to better understand the effects of applying this training to healthy individuals. We searched five databases—PubMed, EMBASE, Scopus, Lilacs, and Scielo—with the following inclusion criteria: (a) peer-reviewed articles published in English; (b) analysis of adult participants who had no musculoskeletal injuries or diseases that might impair balance control; and (c) use of methods containing at least a pre-test, exclusive single leg balance training, and a post-test assessment. We included 13 articles meeting these criteria and found that single leg balance training protocols were effective in inducing balance control gains in either single- or multiple-session training and with or without progression of difficulty. Balance control gains were achieved with different amounts of training, ranging from a single short session of 10 minutes to multiple sessions totaling as much as 390 min of unipedal balance time. Generalization of balance gains to untrained tasks and cross-education between legs from single leg balance training were consistent across studies. We concluded that single leg balance training can be used in various contexts to improve balance performance in healthy individuals. These results extend knowledge of expected outcomes from this form of training and aid single leg balance exercise prescription regarding volume, frequency, and potential progressions.
Development of the “Belief of Affective Perspective-Taking Ability Scale”
Authors: Suzuki Yudai , Sakamoto Shinji
Published: January 2022

This study aimed to develop the Belief of Affective Perspective-Taking Ability Scale (BAPTAS). The belief of affective perspective-taking ability is defined as the tendency of individuals to believe people are generally capable of taking others’ perspectives and imagining others’ emotions, and we developed 17 items for BAPTAS. The participants in the study comprised 151 university students, who answered the BAPTAS, Experience of Receiving Empathy Scale (ERES), perspective-taking tendency, Interpersonal Trust Scale (ITS), and UCLA loneliness scale in Japanese (ULS-J). Thus, 13 items were constructed, and the scores of BAPTAS showed a normal distribution ( M = 4.52, SD = 0.97). BAPTAS is positively related to ERES, a perspective-taking tendency and ITS, and it is negatively related to ULS-J. The relations between BAPTAS and other scales correspond to our previous expectations. We discussed both the potential contribution of BAPTAS to perspective-taking and empathy research and the need to examine its validity experimentally. Our hypothesis was supported, and the validity and reliability of BAPTAS were confirmed.
Relationality as a Lens for Policy Analysis: Preserving Harmony in a Triangular Cooperation Project to Strengthen Gender Mainstreaming in Fiji
Authors: Alta Aditya , Mukhtarov Farhad
Published: January 2022

Policy has been mostly approached as a rational project of setting goals and establishing rules and roles to achieve them. Alternative approaches to policy have been referred to as post-positivist, critical-reflexive and relational. They all emphasize emergent, co-evolutionary and relational aspects of policy work that cannot be reduced to rational choice and reasoning-based models alone. A shared element of such frameworks is the focus on relationships, which are seen not just in a narrow sense of the “logic of appropriateness,” but as a force that shapes actors’ identities, interests and power. Following relational analytical approaches, we analyze a triangular development cooperation project funded by the United States Agency for International Development (USAID) and the Government of Indonesia in order to strengthen gender mainstreaming (SGM) of Fijian government. Through attention to relationality as it shapes actors’ identities and narratives, we demonstrate how a different form of learning employed by each actor facilitated harmony in the project. A key mediating factor in the smooth project co-evolution that we observed, was the ambiguous project design and vaguely articulated goals, supported by fragmented project setup and reporting. Such ambiguity allowed formulation of multiple versions of the project’s outcomes for multiple audiences. However, it also resulted in little impact on the ground in Fiji. Our findings support persistent criticism of development aid projects in small island states for rarely addressing problems of target populations.
Reconceptualizing school safety for Black students
Authors: Heidelburg Kamontá , Phelps Chavez , Collins Tai A.
Published: January 2022

Ensuring a psychologically and physically safe learning environment for students and staff is necessary for students to learn and grow and for teachers to teach. However, for Black students and other marginalized students, the school environment is often physically and emotionally unsafe and they are targeted by anti-Black policies and practices, ultimately producing inequitable outcomes. As such, school safety must be reexamined and reconceptualized to promote a safe, secure, and welcoming environment for Black students. In this article, we will discuss the school-based experiences of Black students in American schools with a particular focus on Black students’ physical and emotional safety. Furthermore, implications and recommendations for establishing safe, affirming, and culturally relevant educational spaces for Black students are provided.
What Motives Do People Most Want to Know About When Meeting Another Person? An Investigation Into Prioritization of Information About Seven Fundamental Motives
Authors: Billet Matthew I. , McCall Hugh C. , Schaller Mark
Published: January 2022

What information about a person’s personality do people want to know? Prior research has focused on behavioral traits, but personality is also characterized in terms of motives. Four studies ( N = 1,502) assessed participants’ interest in information about seven fundamental social motives (self-protection, disease avoidance, affiliation, status, mate seeking, mate retention, kin care) across 12 experimental conditions that presented details about the person or situation. In the absence of details about specific situations, participants most highly prioritized learning about kin care and mate retention motives. There was some variability across conditions, but the kin care motive was consistently highly prioritized. Additional results from Studies 1 to 4 and Study 5 ( N = 174) showed the most highly prioritized motives were perceived to be stable across time and to be especially diagnostic of a person’s trustworthiness, warmth, competence, and dependability. Findings are discussed in relation to research on fundamental social motives and pragmatic perspectives on person perception.
“It’s your body, it’s part of who you are!”: Influences upon collegiate vocalists’ performance self-efficacy beliefs
Authors: Lewis Megan C , Hendricks Karin S
Published: January 2022

Fostering accurate musical self-perceptions may be particularly challenging when developing singing technique, where self-assessment is complicated by the close physiological and emotional relationship between the performer and the body-instrument. The aim of the present study was to investigate how vocal students’ beliefs in their performance capabilities were influenced by the four sources of self-efficacy and other personal/contextual factors. Nine vocalists at a private university in the western United States completed the Vocal Performance Self-Efficacy Survey, participated in two follow-up interviews, and provided written reflections about experiences that fostered or hindered their performance belief. Participants reported that they moved from a reliance on external assessments of capability to self-appraisal as they (a) refined technique through practice and performance, (b) observed coping and master models, (c) managed feedback from others, (d) attuned to physiological and emotional sensations, and (e) exercised cognitive self-regulation. Eight of nine interview participants reported that physiological and affective states most affected their performance belief. Findings indicate the importance of nurturing vocal students’ performance beliefs by utilizing the four sources of self-efficacy, fostering qualities of persistence and resilience, teaching agentic causation, fostering productive student/teacher relationships, and creating emotionally safe learning and performance environments.
Public support for collaborative workspaces: Dispersed help to a place-based phenomenon?
Authors: Avdikos Vasilis , Papageorgiou Antigoni
Published: January 2022

The paper maps a range of policy initiatives for the support of collaborative workspaces (hereafter CWS) by examining the different ways such spaces have been funded, through what instruments, as well as what are the dominant reasons for receiving public support of any kind in urban and rural areas. Our analysis explores policy intentions as well as the funding tools of specific policy programmes that have supported CWS. This contribution aims to provide a categorization of existing policy initiatives about CWS and wishes to connect such policies with wider creative and urban and regional policy debates regarding the turn towards entrepreneurial forms of work and development in an era of economic uncertainty. The paper traces the evolution of CWS by examining the three overlapping waves of CWS and the specific reasons for their emergence. Then, it turns its focus on existing funding schemes and instruments for CWS, identifying five distinct categories of public support. It concludes by testifying in favour of understanding – and thus, supporting – CWS as place-based and site-specific phenomena. Thus, it calls for a new positioning of CWS into place-based development agendas, whilst taking into consideration the singularity of the place, the multiplicity of the actors and the particular institutional conditions and socio-economic characteristics involved.
An Integrated mHealth Campaign to Reduce the Risk of Falling for Older Adults
Authors: Brew-Sam Nicola , Chib Arul , Torres Arah Ysabelle Fondevilla , Ng Jing Xuan Joshua , Wong Yi Ting Jade , Sze-G Yeo
Published: January 2022

The number of falls among older adults is rising due to an aging population worldwide. An integrated communication campaign utilizing mHealth (mobile health) encouraged older adults to perform strength, balance, and flexibility exercises to reduce their risk of falling. Campaign development was guided by a mixed-method approach which incorporated expert interviews ( N = 3), qualitative interviews ( N = 22), and a quantitative baseline pre-campaign survey ( N = 274) with older adults. We evaluated the campaign impact with a pre-post survey analysis (post n = 141). Impact was measured by knowledge, attitudes, self-efficacy, and behaviors as key Social Cognitive Theory factors to exercise adoption. Results showed that respondents with campaign exposure had a significant increase in all factor scores from pre- to post-campaign survey, which was significantly higher in the group with campaign exposure. The impact evaluation illustrated how digital mobile channels effectively provide means to reach older adults to reduce their risk of falling.
Factor Structure and Longitudinal Measurement Invariance of the Achievement Goal Questionnaire with a Korean Adolescent Sample
Authors: Yi Soohyun , Pereira Nielsen , Ahn Inok , Lee Soonmook
Published: January 2022

For decades, achievement goal theory has been extensively used, but empirical research still requires a clearer understanding of the underlying factors conceptualized and measured during secondary school periods. In light of the increasing use of longitudinal studies in motivation research, this study aims to investigate the longitudinal measurement invariance of the Achievement Goal Questionnaire (AGQ) with the longitudinal panel data of 5071 adolescents. Findings support the consistent use of the 2×2 model across eighth to eleventh grades, although inter-factor correlations were inflated at eleventh grade. Partial strict longitudinal measurement invariance was supported for testing equivalence between the tenth and eleventh grades. Regarding the relations to other variables, the four individual factors of achievement goals have distinct properties in relation to other variables as theoretically hypothesized; and the patterns of the relationship were stable from eighth to eleventh grades.
Concept Mapping in Technology-Supported K-12 Education: A Systematic Review of Selected SSCI Publications From 2001 to 2020
Authors: Chang Chun-Chun , Hwang Gwo-Jen , Tu Yun-Fang
Published: January 2022

Concept maps have been verified as an effective learning tool in technology-supported learning environments, in particular, in K-12 education. To enable educational technology researchers and school teachers to thoroughly know the research foci and applications of concept maps in technology-supported learning environments for K-12 education (CM-K12), the present study conducted a systematic review of studies published in seven SSCI (Social Science Citation Index) journals of educational technology by referring to the technology-based learning model. The review results showed that concept maps mostly played the role of a personal Mindtool and a collaborative Mindtool, and were mainly applied in elementary schools. The majority of elementary school teachers employed concept maps as a collaborative Mindtool (for a learning group), a personal Mindtool (for individual students), and a learning design tool. As for secondary school teachers, concept maps were mostly adopted as an assessment and evaluation tool, personal Mindtools, and collaborative Mindtools. In terms of application issues, the most adopted medium was desk-top computers, and the most adopted application domains were science, engineering, and language. The research focus explored the most in CM-K12 research was cognition, followed by affect and learning behavior. Based on the findings, several recommendations are proposed.
Unique Barriers to Workplace Health Promotion Programs by Wage Category: A Qualitative Assessment of Secondary Data
Authors: Stiehl Emily , Bales Susan L. , Jenkins Kristi Rahrig , Sherman Bruce W.
Published: January 2022

Purpose

To understand barriers around accessing or using workplace health promotion (WHP) programs among workers in different wage categories.

Approach

We conducted qualitative analysis of responses to three open-ended questions about WHP program participation, collected as part of an existing WHP program evaluation. Setting: A large mid-western university.

Participants

Of the 20,000 employees emailed an online survey, 3,212 responded (16.1%). The sample was mostly female (75%), white (79%), and comprised of staff members (84%). The average age was 44 years and 67% had annual incomes <$75,001.

Method

We used NVivo-12 Plus and two coders to apply Grounded Theory on the open-ended questions and identify emergent themes.

Results

Although most respondents were happy with the program, differences across wage categories emerged around time, financial incentives, commute, workload, and organizational policies/support. Employees at all wage levels were enthusiastic about creating a culture of health but needed different cultural supports to do so. For instance, higher-wage workers needed to overcome self-made time constraints, while lower-wage workers needed supervisor support to overcome coverage constraints that prevented participation.

Conclusion

The unique participation challenges experienced by employees in different wage categories provide justification for WHP programs that can better accommodate the participation barriers of all employees. While some programs may simply require more flexible offerings, supervisors may need to be trained to support and foster healthy environments.
What Is Healthy Eating? Exploring Profiles of Intuitive Eating and Nutritionally Healthy Eating in College Women
Authors: Belon Katherine E. , Serier Kelsey N. , VanderJagt Hayley , Smith Jane Ellen
Published: January 2022

Purpose

Research suggests that food’s nutritional content and the feelings and behaviors associated with eating contribute to overall health, yet these constructs are rarely considered simultaneously. The current cross-sectional study investigated healthy eating profiles in college women that included both nutritional quality and intuitive eating (IE), with IE being an eating style that prioritizes physiological hunger/satiety cues and minimizes dieting and emotional eating.

Design/Setting/Subjects

Undergraduate women ( n = 352) completed an online assessment and daily diaries (80% retention).

Measures

Nutritionally healthy eating, IE, dieting, body dissatisfaction, disordered eating, and psychological health were examined.

Analysis

Latent profile analysis explored patterns of nutritionally healthy eating and IE, and determined how these patterns related to psychological and disordered eating outcomes.

Results

A four-profile solution emerged: 1) Dieting (high nutritionally healthy eating + intermediate IE), 2) Unhealthy Eating (low nutritionally healthy eating + low IE), 3) Intuitive Eating (moderately high nutritionally healthy eating + high IE), and 4) Non-Dieting (low nutritionally healthy eating + intermediate IE). These profiles significantly differed from one another, such that the Intuitive Eating and Non-Dieting profiles reported lower psychological distress, body mass index, and disordered eating compared to other profiles, while the Dieting and Unhealthy Eating profiles showed the healthiest and poorest nutritional eating, respectively.

Conclusion

These findings suggest that IE and nutritionally healthy eating are distinct factors in conceptualizing the eating patterns of college women, and both should be considered when developing interventions. Future research should replicate these findings in larger/more diverse samples and examine eating profiles longitudinally.
Effects of Narrative Messages on Key COVID-19 Protective Responses: Findings From a Randomized Online Experiment
Authors: Iles Irina A. , Gaysynsky Anna , Sylvia Chou Wen-Ying
Published: January 2022

Purpose

We investigated the effectiveness of narrative vs non-narrative messages in changing COVID-19-related perceptions and intentions.

Design/Setting

The study employed a between-subjects two-group (narratives vs non-narratives) experimental design and was administered online.

Subjects/Intervention

1804 U.S. adults recruited via Amazon MTurk in September 2020 were randomly assigned to one of two experimental conditions and read either three narrative or three non-narrative messages about social distancing, vaccination, and unproven treatments.

Measures

Perceptions and intentions were assessed before and after message exposure (7-point scales).

Analysis

Using multivariable regression, we assessed main effects of the experimental condition (controlling for baseline measures) and interactions between the condition and pre-exposure perceptions/intentions in predicting post-exposure outcomes.

Results

Compared to non-narratives, narratives led to (1) less positive perceptions about the benefits of unproven treatments ( M narrative = 3.60, M non-narrative = 3.77, P = .007); and (2) less willingness to receive an unproven drug ( M narrative = 3.46, M non-narrative = 3.77, P < .001); this effect was stronger among individuals with higher baseline willingness to receive unproven drugs (baseline willingness = 2.09: b = −.06, P = .461; baseline willingness = 3.90: b = −.30, P < .001; baseline willingness = 5.71: b = −.55, P < .001). Narratives also led to more positive perceptions of vaccine safety/effectiveness, but only among individuals with lower baseline vaccine perceptions (baseline perceptions = 4.51: b = .10, P = .008; baseline perceptions = 5.89: b = .04, P = .167; baseline perceptions = 7: b = −.01, P = .688).

Conclusion

Narratives are a promising communication strategy, particularly for topics where views are not entrenched and among individuals who are more resistant to recommendations.
The Role of Implicit Biases and Explicit Attitudes Toward the Poor in Donation Choices
Authors: Fung Joey , Fung Winnie , Israel Rosales Aaron , Jin Joel , Pettit Ramanda Mallery
Published: January 2022

We examined how individuals’ implicit biases and explicit attitudes toward the poor may be associated with the types of social programs people chose to give to. Participants included 112 students. When people believed that poverty is due to internal causes (e.g., people are lazy) or if they held implicit biases that the poor are irresponsible, they were more likely to avoid unconditional cash transfer (UCT) or in-kind donation (IKD) and choose conditional cash transfer. When people believed that poverty is due to external (e.g., poor economy) or cultural causes (e.g., born poor), they were more likely to choose UCT or IKD. People’s affective/positive feelings toward the poor using implicit and explicit measures were not associated with donation choice. Our study highlighted differences between affective feelings versus cognitive beliefs about the poor, and that both implicit and explicit forms of cognitive beliefs can be associated with one’s giving choices.
Marketisation and Regulatory Labour in Frontline Disability Work
Authors: van Toorn Georgia , Cortis Natasha
Published: January 2022

In many liberal welfare states, market-based reforms aimed at enhancing competition and choice in disability services have necessitated extensive regulatory reforms to ensure quality service provision. This article explores how the changing regulatory environment surrounding an individualised funding scheme is transforming frontline disability work. Drawing on data from a survey of 2341 Australian disability support workers, the article contributes to sociological understandings of market regulation by foregrounding the importance of frontline workers’ labour to the regulation of social service markets. Various regulation-related tasks and duties are identified which, while practically embedded among the client-focused components of care work previously documented, are analytically distinct from them. This category of undertheorised, unrecognised, often unpaid work is referred to as ‘regulatory labour’. The article illuminates the mechanisms through which workers enact and resist regulatory processes and help absorb market risks and failures in ways previously underexplored in theories of marketised social care.
Public administration reform and political will in cases of political instability: Insights from the Israeli experience
Authors: Cohen Nissim
Published: January 2022

How do public administration reforms develop in cases of political instability? Administrative reform has always been on the agenda of governments. Ample literature discusses its necessity and the factors that are associated with both its successes and failures worldwide. Nevertheless, only a few studies discuss the impact of political instability on public administration reform. Focusing on the Israeli experience, we explore public administration reform in the context of political instability. Using content analysis and in-depth interviews, we highlight how political instability adds more costs to politicians’ cost-benefit calculations about actively promoting public administration reform, as well as how it blocks their desire to engage in mundane work when large, visible reforms have been proposed. Our findings indicate that the problems of non-governability and political instability that create the need for administrative reform also create powerful barriers to it—particularly the lack of political will.
Evaluating the J-integral of mode I crack in gradient nanocrystalline metals with residual stress induced by surface mechanical treatment
Authors: Qiu Linxi , Yang Fan , Zhang Zhennan , Zhao Jinfeng
Published: January 2022

In gradient nanocrystalline metals, the grain size variation usually comes with the compressive residual stress induced by mechanical surface treatments such as surface mechanical attrition and severe shot peening. This paper focused on the fracture of gradient nanocrystalline metals with the residual stress that is introduced during the mechanical surface treatment. The J-integral of a mode I crack in the gradient nanocrystalline metal with different residual stress was calculated using finite element method. ABAQUS/Python scripts were developed to automatically create the gradient material, exert the residual stress and calculate the J-integral. By employing the empirical residual stress formula of sinusoidal decay type, a parametric study was carried out to investigate the effects of two characteristic features of residual stress, that is, the magnitude and the compressive zone depth, on the calculated J-integral. The results reveal that J-integral is significantly influenced by the residual stress. Specifically, the J-integral will decrease as the magnitude of residual stress increases. As the compressive zone depth increases, the J-integral first decreases and then increases. This indicates that the induced residual stress, along with the surface grain size variation, contributes jointly to the enhanced toughness of the gradient nanocrystalline metals.
An investigation on mechanical and microstructural evolution of stationary shoulder friction stir welded aluminum alloy AA7075-T651
Authors: Hammad Ali S , Ahmed Mohamed MZ , Lu Hong , El-Shabasy Adel B , Alzahrani Bandar , El-Sayed Seleman Mohamed M , Zhang Yongquan , El Megharbel A
Published: January 2022

The stationary shoulder friction stir welding (SSFSW) technique promotes new opportunities for welding material. In the current work, a special setup of SSFSW was designed and manufactured in only three parts according to the homemade friction stir welding (FSW) machine dimensions and specifications. This setup with minimum parts is easily adjustable beside it facilitates fast control of the tool pin length. This gives the design more advantages than the previous designs published for the same purpose. Two different parameters were used with the SSFSW setup to butt weld samples of AA7075-T6 of 5 mm thick. Various welding travel speeds of 25, 50 mm/min, and 75 mm/min and different values of Z-force of 20, 25 KN, and 50 KN were used to evaluate the effect of the SSFSW parameters on the joints’ quality and properties. The results confirmed that sound joints were produced without internal or surface defects. In addition, the joints are characterized with a smooth surface finish compared to the conventional FSW joints. A narrow heat affected zone around the nugget due to the elimination of heat generation by the shoulder. The tensile strength of welded samples increases with increasing the vertical force with the maximum tensile strength of 418.7 MPa at a rotational speed of 600 r/min, a welding speed of 50 mm/min, and 50 KN Z-force. This implies that the vertical applied force upon SSFSW is an important parameter in controlling the joint properties. Analysis of the hardness distribution across the weld cross-section shows slight reduction in the heat affected zone.
A modal self-excitation method of tensegrity robots
Authors: Li Xin , He Jingfeng
Published: January 2022

A tensegrity robot is a type of soft-rigid system, whose high compliance is prone to induce structural vibrations which traditionally should be avoided. However, a stable limit cycle oscillation at a natural frequency can be exploited to improve motion efficiency of tensegrity robots. By constructing a modal self-excitation system, we can produce limit cycle oscillation for tensegrity robots. Therefore, in this paper, we propose a method to realize modal self-excitation of under-actuated tensegrity robots. A task-space second-order structural model of a tensegrity robot is developed and a mapping between forces of cable-space and that of task-space is derived. Meanwhile, we propose a cable sensitivity vector from modal shape to guide the selection of active cables in the tensegrity robot. A modal self-excitation system is designed by combining a bandpass filter with a describing function into the control system. In this way, a limit cycle oscillation at a frequency can be formed close to the desired natural frequency. The stability of this limit cycle oscillation is analyzed by perturbation method. Modal switching excitation is also achieved by switching between different modal excitation loops online. The effectiveness of the proposed modal self-excitation method for tensegrity robots is verified by several numerical simulations and tests.
Influence of the reasonable crack initiation force obtained by coupling AE parameters and stress-strain on low-stress cropping quality
Authors: Xu Jiayi , Zhang Dexiao , Zhou Qiang , Sun Xudong , Yang Ning , Guo Weijian , Fu Shulin , Zhang Lijun
Published: January 2022

In view of the problem that it is difficult to accurately obtain the crack initiation force required for the metal bar with V-shaped notch in the low-stress precision cropping, a new method for synchronous measurement of coupling AE parameters and stress–strain is proposed, and a corresponding test platform is also established. By analyzing the ringing count and RMS parameters of AE, it is found that the crack at the tip of V-shaped notch begins to appear at the boundary between the crack accumulation area and the plastic failure area. At the moment, the reasonable crack initiation force for metal bar with V-shaped notch can also be determined by coupling the value of strain. Based on it, a new constant loading curve based on the FR is built. The results show that by means of the constant loading curve, the crack initiation time and the area of bar transient breaking zone are reduced by 63.6% and 51.2%, respectively, compared with ones of the traditional linear loading methods. Further research based on XFEM shows that the initial crack depth is between 0.25mm and 0.4mm, and the cracking angle and the crack offset distance can also meet the precision cropping requirement, which provides a technical guarantee for truly improving the cropping quality.
Adaptive Fractional-order Non-singular Fast Terminal Sliding Mode Control Based on Fixed Time Observer
Authors: Shi Ran , Zhang Xin
Published: January 2022

Aiming at the problem of low tracking accuracy of the manipulator in the presence of model parameter errors and external disturbance, this paper proposes an adaptive fractional-order non-singular fast terminal sliding mode (AFONFTSM) controller based on a fixed-time disturbance observer (FTDO). The controller is split into three portions. First, a fractional-order non-singular fast terminal sliding mode (FONFTSM) surface is designed to improve the tracking accuracy and convergence speed of the error state. Second, to enhance the performance of the system state in the approaching mode, an adaptive variable exponential power reaching law (AVEPRL) is designed, which changes the coefficient of the exponential term through the size of the system state. Meanwhile, adaptive control is used to modulate one item of the reaching law, which improves the anti-interference of the system. In the end, the real-time estimation of the external disturbance is carried out by the FTDO, which solves the problem that the magnitude of the external disturbance is difficult to be determined in the actual engineering. And the stability is verified by the Lyapunov theory. The simulation results display that the controller raised in this paper has better tracking precision, faster convergence speed, and stronger robustness.
A review of research into aerodynamic concepts for high speed trains in tunnels and open air and the air-tightness requirements for passenger comfort
Authors: Srivastava Sandeep , Sivasankar Govindu , Dua Gautam
Published: January 2022

India will soon have its first line with trains operating at internationally defined standards of high speed (exceeding 250 km/h). On the MAHSR (Mumbai-Ahmedabad High Speed Railway) corridor modern high speed trains will routinely operate at speeds as high as 200 mph (320 km/h). At high speed, trains are capable of generating significant aerodynamic effects including wind gusts and air pressure changes, which makes it necessary to address HSTs’ aerodynamics during the planning stage of high-speed rail (HSR) lines. The dynamic pressure tightness in train cars is also an important factor in the design of future railway tunnels, together with the medical health criterion and pressure comfort criteria. With increasing speed, the requirements of pressure tightness increases, which are explained and illustrated in this study. The current study is based on prior work done in the field of aerodynamic effects of HSTs, international standards, and design practice followed in existing HSR projects. Effort has been made to bring various studies in one place for ready reference. Parameters such as pressure comfort, optimized distance between center of track, wayside structural design, and tunnel cross-section requirements are explained. Based on the study and established relation by different authors, the pressure difference calculation is done for the MAHSR project for different scenarios, and passenger comfort was deduced. In this study, three major aspects of the aerodynamic pressure effect on the rolling stock and surroundings are examined, and each aspect is discussed distinctly: (1) open-air considerations: pressure effect on wayside structures, (2) open-air considerations: two trains crossing in the open field, and (3) open-air considerations: tunnel phenomenon: pressure wave effects on trains inside tunnels. The present study and a substantial portion of the existing knowledge base can be extrapolated for use in the future guidelines in India. This study examine the resultant pressures on wayside structures, the resultant pressures on adjacent trains, and pressure wave effects in tunnels (associated analyses were performed to determine the appropriate cross-sectional area of the tunnels), respectively. It includes basic aerodynamic concepts, influencing factors, measurement and calculation of pressure between trains, known and potential impacts, mitigations, standards, conclusions, and recommendations.
Disease Knowledge, Self-Efficacy, and Quality of Life in Patient With Hypertensive Nephropathy
Authors: Chen Yen-Yen , Lee Mei-Chen , Wu Shu-Fang Vivienne , Liu Yueh-Min , Chen Hui-Mei
Published: January 2022

The purpose of this study is to investigate the relationships among disease knowledge, self-efficacy, and quality of life in patients with hypertensive nephropathy. A cross-sectional and correlational design is employed in this study, and a total of 213 participants are collected by convenience sampling from the outpatient Department of Nephrology of a regional teaching hospital in Taiwan. The research instruments include the Hypertensive Nephropathy Knowledge Instrument, the Chronic Kidney Disease Self-Efficacy Instrument, and the Medical Outcome Study Short Form-12, and stepwise multiple regression analysis is used to test the explanatory power of each significantly-correlated independent variable regarding the quality of life. The results show that the higher the disease knowledge, the better the self-efficacy, and the better the quality of life, and self-efficacy is the most important predictor of the quality of life.
How it Ends: Brief Remarks on Reading 2 Thessalonians 2:1-12
Authors: Ziegler Philip G.
Published: January 2022

This short essay reflects theologically upon aspects of the enigmatic passage 2 Thessalonians 2:1-12 and contends that while certainly directed at assuaging the eschatological anxieties of the Christian congregation to whom it is addressed, this passage is not, as is often suggested, uninterested in eschatological doctrine as such. Rather, I argued that it is precisely the apocalyptic vision of the victorious and eloquent epiphany of the Lord that funds the peace and hope to which Christians are called in the midst of tumultuous times, and that this orientation is decisive for both faith and theology.
Maternal Childhood Maltreatment History and Child Behavior Problems: Developmental Patterns and Mediation via Maternal Depressive Symptoms and Parenting Behavior
Authors: Harris Madeleine , MacMillan Harriet , Mepham Jennifer , Joshi Divya , Wekerle Christine , Atkinson Leslie , Gonzalez Andrea
Published: January 2022

Maternal exposure to childhood maltreatment (CM) is associated with offspring behavioral problems; however, little work has examined these associations longitudinally across child development. This study examined the effects of maternal history of CM on trajectories of child internalizing and externalizing behavior measured from toddlerhood to preschool, and the role of maternal depressive symptoms and parenting behavior as potential mediators. Participants included 115 mother–child dyads recruited from a hospital maternity ward. Maternal CM was measured at 3-months postpartum. At 18, 36, and 60 months, maternal depressive symptoms and child behavior were assessed via maternal report and parenting behavior was assessed through direct observation. Findings indicated that children of mothers exposed to CM demonstrated poorer trajectories of problem behavior across early childhood. Maternal depressive symptoms mediated the relation between CM and children’s internalizing problems. Findings highlight the importance of screening for maternal depressive symptoms and early intervention for maternal and child mental health.
Predictors of Prosecutorial Decisions in Reports of Child Sexual Abuse
Authors: Block Stephanie D. , Johnson Hannah M. , Williams Linda M. , Shockley Kristy L. , Wang Eric , Widaman Keith F.
Published: January 2022

A retrospective examination of 500 child sexual abuse reports to prosecutor’s offices analyzed case progress and predictors of attrition, including details about alleged perpetrator(s), victim(s), their families, and other case characteristics. Less than one in five cases proceeded to prosecution. For the full sample, we describe all outcomes and differentiate prosecutors’ decisions to (a) intake/close, (b) investigate/close, or (c) prosecute; these stages comprise a 3-level dependent variable. Because it is important to understand which variables are associated with progress to each stage, we examined unique predictors of the decision to “investigate,” and to “prosecute.” Our multivariate analyses examine 325 cases with a perpetrator aged 16 and older. Caregiver support and perpetrator age were significant predictors across all outcome variables, while other factors were barriers to the “prosecute” decision only. Results highlight the complexities of case characteristics that are important at different stages of prosecutorial decision-making and inform future interventions.
Anonymous Reporting Systems for School-Based Violence Prevention: A Systematic Review
Authors: Messman Elizabeth , Heinze Justin , Hsieh Hsing-Fang , Hockley Nicole , Pomerantz Naomi , Grodzinski Alison , Scott Briana , Goldstein Noah , Zimmerman Marc
Published: January 2022

Anonymous reporting systems (ARS) have been widely implemented in schools across the United States as a violence prevention strategy. The current study systematically reviewed the published literature on ARS in U.S. schools (including public and private k-12 schools, colleges, and universities) over the past 25 years to examine the effectiveness of ARS as a school safety and violence prevention strategy. We conducted a comprehensive literature search which identified just four studies pertaining to ARS in schools. Of note, only one of these studies was published in a peer-reviewed journal. Results from this systematic review point to the need for more empirical studies on the effectiveness of ARS as a violence prevention strategy. Findings from this review also highlight the wide variation across schools in the type of ARS used, the mode of implementation, and associated educational and training components. This review is a first step in documenting an evidence-base for ARS which will be useful in guiding educators and policymakers about best practices for the use of ARS in schools.

Impact Statement

Anonymous reporting systems (ARS) have been used as a violence prevention strategy in schools by providing a means for individuals within a school community to safely and securely report information about potential violence or concerns about mental health, for example, through an anonymous hotline or reporting app. Despite widespread implementation of ARS in schools, as well as mandates for reporting systems in schools in 21 states, there is limited evidence on the effectiveness of ARS for school violence prevention, and information about best practices for ARS implementation is lacking. This systematic review aims to summarize the current research on the effectiveness of ARS as a school safety and violence prevention strategy, which is an important step in building an evidence-base to guide schools and policymakers about best practices.