bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital planning and guided surgery in oral rehabilitation
Authors: Santos Larissa Braga dos , Oliveira Adriano Relvas Barreira de , Lefrançois Mauro , Azevedo Marcos Venício , Sotelo Pablo , Sotelo Laura
Published: September 2020

Digital planning of the prosthesis associated with surgical planning increased predictability, since surgical guides indicate the best place for implant installation, thus reducing the number of complications, and the CAD/CAM system provides predictability in the preparation of final restorations, according to the procedure previously planned. Our study reported a digital workflow used for the guided installation of two dental implants in regions 14 and 16, extraction of tooth 15 and installation of a fixed prothesis over implants. After anamnesis and clinical evaluation, intra- and extra-oral photographs of the patient were performed, molding the upper arch with polyvinylsiloxane (2-step putty/light-body technique) and requesting computed tomography. The plaster model obtained was sent to the laboratory and scanned. The generated file (STL) was used to create a diagnostic wax-up that was aligned to the tomography (in DICOM format), enabling the three-dimensional planning of the implants, which generated a partial printed surgical guide after approval of the dentist. After six months, the patient received the provisional fixed prosthesis printed in PMMA (polymethylmethacrylate) on an intermediate in PEEK (polyetheretherketone) aiming to condition an emergency profile to receive a definitive prosthesis two months later, with zirconia-milled infrastructure on a ti-base. The correct understanding of the operator about the steps of the digital workflow (diagnosis, prosthetic planning, surgical planning, guide preparation, temporary and final restorations) gives the operator improved predictability at the time of surgery as well as satisfactory aesthetic and functional result of definitive restorations.
A new species of Isoperla (Plecoptera: Perlodidae) from China
Authors: CAO ZHISHAN , WANG YING , LI WEIHAI
Published: September 2020

A new species of the perlodid genus, Isoperla Banks, I. sejila sp. nov., is described and illustrated from the Tibet Autonomous Region of southeastern China. The everted aedeagus of the male is described and the relationships with other species of this genus known from China are discussed.
Walk the (Gendered and Racialized) Line: Retrospective Consecration and the Rock and Roll Hall of Fame
Authors: Bledsoe Ashlee
Published: September 2020

Cultural consecration demonstrates the values of a field, and it is influenced by several different factors. Previous research on consecration in rock music has examined the impact of critical, professional, and popular legitimacy, as well as the gender of the performers, on the likelihood of albums being retrospectively consecrated. The study builds on and extends this research by examining the impact of these different forms of legitimacy and gender, while also examining the impact of performers’ race on (a) the likelihood of being inducted into the Rock and Roll Hall of Fame and (b) the wait-time that performers face in that induction.
Relation Between Globulin, Fibrinogen, and Albumin With the Presence and Severity of Coronary Artery Disease
Authors: Deveci Bülent , Gazi Emine
Published: September 2020

The albumin to globulin ratio (AGR) is used as a prognostic marker in acute ischemic cardiovascular events. We investigated whether serum AGR, fibrinogen, and fibrinogen to albumin ratio (FAR) are related to the presence and severity of coronary artery disease (CAD). Patients who underwent coronary angiography procedures were analyzed retrospectively. The severity of CAD was assessed by the Gensini score. The study population (3031 patients; 1071 females and 1960 males) was divided into 3 tertiles based on AGR values. Gensini score, lipid levels, diabetes mellitus (DM), hypertension (HT), age, and fibrinogen level were higher in the low AGR group. Pearson correlation analysis showed that AGR ( r = −0.068, P < .001) was negatively and fibrinogen ( r = 0.187, P < .001) was positively correlated with the Gensini score. Male gender, HT, smoking, DM, age, high triglyceride (TG) level, low-density lipoprotein cholesterol (LDL-C) >160 mg/dL, estimated glomerular filtration rate (eGFR) <60 mL/min, and fibrinogen level >3.5 g/L were independent predictors of CAD. Male gender, age, eGFR, DM, LDL-C, TG, and FAR had an independent positive relation to the Gensini score. In conclusion, similar to traditional risk factors, plasma fibrinogen and albumin levels showed a close relation with the presence and severity of CAD.
Exploring Teacher Attrition in Urban China through Interplay of Wages and Well-being
Authors: Liu Ji
Published: September 2020

Teacher attrition is a chronic challenge facing many education systems, and has been shown to negatively impact education quality and equity. Common explanations rooted in occupational choice theory identify pecuniary and non-pecuniary rewards as critical factors in motivating and retaining teachers. Using China Household Income Project (CHIP) urban dataset, which contains detailed information on teacher career decisions, this study examines these theoretical stipulations by simultaneously modeling teacher career decisions, wage compensation, and on-the-job well-being. Probit panel regression results demonstrate that a 10% increase in teacher wage and well-being gaps, relative to comparable professionals, predicts a 7.9% and 32% lower probability of retention respectively, with effects mostly operating through teacher well-being.
Measuring Driver Perception: Combining Eye-Tracking and Automated Road Scene Perception
Authors: Stapel Jork , El Hassnaoui Mounir , Happee Riender
Published: September 2020

Objective

To investigate how well gaze behavior can indicate driver awareness of individual road users when related to the vehicle’s road scene perception.

Background

An appropriate method is required to identify how driver gaze reveals awareness of other road users.

Method

We developed a recognition-based method for labeling of driver situation awareness (SA) in a vehicle with road-scene perception and eye tracking. Thirteen drivers performed 91 left turns on complex urban intersections and identified images of encountered road users among distractor images.

Results

Drivers fixated within 2° for 72.8% of relevant and 27.8% of irrelevant road users and were able to recognize 36.1% of the relevant and 19.4% of irrelevant road users one min after leaving the intersection. Gaze behavior could predict road user relevance but not the outcome of the recognition task. Unexpectedly, 18% of road users observed beyond 10° were recognized.

Conclusions

Despite suboptimal psychometric properties leading to low recognition rates, our recognition task could identify awareness of individual road users during left turn maneuvers. Perception occurred at gaze angles well beyond 2°, which means that fixation locations are insufficient for awareness monitoring.

Application

Findings can be used in driver attention and awareness modelling, and design of gaze-based driver support systems.
Researched on the bias stability of the HRG affected by the temperature and the standing wave azimuth
Authors: Zhao Wanliang , Yang Hao , Song Lijun , Yu Xiangyu , Liu Fucheng , Su Yan
Published: September 2020

The force-to-rebalanced control mode is the main operating mechanism of the HRG, and the standing wave azimuth of the resonator points to the 0° direction. But the bias of the HRG is very sensitive to the change of external physical field environment and it is urgent to improve the bias stability. The relationship between the bias of the HRG and the standing wave azimuth is periodic. When the standing wave azimuth and the damping axis are aligned, the bias error of the HRG will be greatly reduced, and the bias stability of the HRG affected by the temperature can also be improved by changing the azimuth of standing wave. In this paper, the control algorithm and the hardware circuit of the HRG are designed to control the HRG at any standing wave azimuths. The control of the HRG in different standing wave azimuths is realized, and the system temperature experiment is carried out. The experimental results show that the bias of the HRG are significantly different at different standing wave azimuths, and the bias stability of the HRG affected by the temperature can be improved 3 times by changing the standing wave azimuth.
Disturbance rejection control for a wastewater treatment process by a learning approach
Authors: Wei Wei , Chen Nan , Liu Zaiwen , Zuo Min
Published: September 2020

Nonlinearities, uncertainties and external disturbances commonly exist in a wastewater treatment process (WWTP). Those issues present great challenges to the control of the dissolved oxygen (DO) concentration in a WWTP. In this paper, an active disturbance rejection control (ADRC) is utilized to estimate the total disturbance and drive the DO concentration to track the set-value. Simultaneously, an iterative learning strategy is employed to adjust the parameters of an extended state observer (ESO) to improve the accuracy of the estimation and reduce the dependence on experience in determining parameters. By combining the advantages of the ADRC and the iterative learning strategy, an iterative learning based active disturbance rejection control (ILADRC) is constructed, and the close-loop stability is analyzed. The benchmark simulation model No.1 (BSM1) is utilized to confirm the ILADRC. Numerical results show that the ILADRC is more effective in the DO concentration control.
The Association of Executive Functioning With Academic, Behavior, and Social Performance Ratings in Children With ADHD
Authors: Tamm Leanne , Loren Richard E. A. , Peugh James , Ciesielski Heather A.
Published: September 2020

This study investigated the association of a performance-based measure of executive functioning (EF) with academic, social, and behavioral performance ratings in a convenience sample of 153 children aged 5 to 12 (78% male, 83% Caucasian) diagnosed with attention-deficit/hyperactivity disorder (ADHD). Multivariate regression showed that above and beyond age and ADHD severity, poorer EF performance was uniquely associated with more impairment in reading, written expression, and math by teacher report, and more impairment in the overall school and reading domains by parent report. ADHD symptoms were more strongly associated with ratings of impairment in social relationships, organized peer activities, and classroom behaviors than EF performance. Age did not moderate the findings, but younger children were rated as having more trouble with participation in organized activities by parents, as more likely to disrupt class by teachers, and to have problematic relationships with peers by parents and teachers. EF and academic performance appeared worst in the groups seen as highly symptomatic and impaired by both parents and teachers, and by teachers only. EF deficits may be a specific risk factor for academic impairment in children with ADHD.
Shaping Policy in Music Education: Music Teachers as Collaborative Change Agents
Authors: Abril Carlos R. , Gault Brent M.
Published: September 2020

Music educators have experience working in education environments governed by shifting policies and mandates. How can music educators become agents empowered to shape, interpret, and design mechanisms for putting policy into practice? This article describes ways to understand policy and options for responding and contributing to its development and implementation. We examine how music educators have responded to two policy areas that have had a significant impact on music programs and teachers in recent years: (1) learning standards and (2) evaluation of student learning as a component of teacher evaluation. Examples in this article are meant to serve as a case in point for how music educators can become more responsive and actively engaged in policy matters.
How Music Education Policies Come to Be and What Teachers Can Do
Authors: Shaw Ryan D.
Published: September 2020

Policies often directly impact teachers’ lives and practice, requiring them to engage in spite of extremely busy schedules. This article offers encouragement to music educators wanting to be active—and become activists—in education policy. Before becoming active, one must understand how music education policies come to be. I argue that arts education policies mostly come to be indirectly, as an afterthought. This operates in numerous ways, involving collateral damage in other policy-making processes; nongermane, eleventh-hour negotiations; and incomplete or subverted policy implementation. To demonstrate these processes, I reference examples including access to a high-quality music education, content of national and state music standards, and music graduation education requirements. I also offer general recommendations for music educators who wish to advocate for positive change.
Meaning-Making of War Experiences: Stories From Kosova
Authors: Kelmendi Kaltrina , Mulaj Ilirjana , Zymberi Malisa , Kadiri Saranda
Published: September 2020

The research evidence shows that war had many detrimental effects on the mental health, wellbeing, and social functioning of the people of Kosova, which is similar to the findings in many other postconflict societies. However, there are few studies focusing on the process of meaning-making of war experiences and their impacts on resilience and growth. This phenomenological study aimed to explore the lived war experiences of citizens of Kosova from the perspectives of three generations (grandparents, parents and children) through semistructured interviews, which were conducted with 37 participants. Thematic analysis revealed that the journey of the meaning-making of war experiences in Kosova is rather dynamic and reflects the context in which each generational cohort lived and grew. The findings provide a deeper understanding of the strategies used by each generation for meaning-making and how these strategies contributed to resilience and growth. The implications for mental health counselors, social workers, and policymakers are discussed.
Toward the Extension of Antecedents of Compulsive Buying: The Influence of Personal Values Theory
Authors: Tarka Piotr , Harnish Richard J.
Published: September 2020

Although a great deal of research has been conducted on compulsive buying, little if any, research has explored compulsive buying from a wider theoretical perspective, encompassing all types of values as potential drivers of compulsive buying. In particular, no comprehensive research has been conducted in the diagnosis of mechanisms that direct the development of compulsive buying from the perspective of personal values theory. Thus, the objective of the current research was to explore compulsive buying within Schwartz’s value model, as well as examining the role particular values play as predictors of compulsive buying. Data were obtained from randomly selected students (young adults), whose ages ranged from 17 to 25 years-old, enrolled at professional and high schools, and at universities in Poland. Personal values were measured by the Polish version of Personal Values Questionnaire, while compulsive buying propensity was assessed by the Polish version of the Richmond Compulsive Buying Scale. Generally, the study’s hypotheses were supported by SEM analysis. That is, those who held values comprising “Self-Enhancement” and “Openness to Change” were more likely to be compulsive buyers. In contrast, those who held values comprising “Self-Transcendence” and “Conservation” were more likely to be non-compulsive buyers. Compulsive buyers were more self-focused, hedonistic, power- and achievement-oriented than non-compulsive buyers. Finally, values that emphasized importance of communal rather than individualistic goals appeared to prevent compulsive buying.
Identity and Accents: Do Students Really Want to Speak Like Native Speakers of English?
Authors: KONG Melinda L.F. , KANG Hye In
Published: September 2020

There is a growing recognition of diverse settings and different varieties of English and accents. However, there seems to be a lack of research on the investments and views of Expanding Circle students who relocate to study in Asian Outer Circle countries, especially on the identities of proficient speakers and/or teachers of English. This study attempts to fill this gap by examining the perceptions of Korean secondary school students in Malaysia through online questions and face-to-face interviews. Among others, findings suggest that the students had investments not only in English but also in their own sociocultural identities which were connected to their own accents. The students also felt that proficient English speakers and/or teachers should have pronunciation and accents that they could understand and that they were familiar with. Since they could not understand some of their native English-speaking teachers (NESTs), they did not feel that a person needed to be a native speaker in order to be a proficient speaker of English. Neither did they have any desire to imitate native speakers’ accents in learning to be proficient speakers because their own accents could be understood. The findings of this study suggest that NESTs may not necessarily be ideal English speakers with accents that need to be imitated. Instead, teaching and learning English should focus on communication between interlocutors from various contexts.
“We always tell them, but they don’t do anything about it!” Middle School Black girls Experiences with Sexual Harassment at an Urban Middle School
Authors: Harris Johari , Kruger Ann C.
Published: September 2020

Black women and girls are frequently left out of narratives on sexual harassment/sexual violence due to pervasive racism and sexism. Schools contribute to this silence by continuing to overlook the exceptional needs and experiences of Black girls. Therefore, this qualitative study used an intersectional lens to examine Black girls’ experiences with sexual harassment in an urban middle school. Results indicated participants experienced both physical and verbal sexual harassment and felt their concerns were largely ignored or/or minimized by teachers school administrators. Recommendations for creating safe spaces for Black girls in urban middle schools are provided.
Racial and Ethnic Disparities, Referral Source and Attrition From Outpatient Substance Use Disorder Treatment Among Adolescents in the United States
Authors: Marotta Phillip L. , Tolou-Shams Marina , Cunningham-Williams Renee M. , Washington Durrell Malik , Voisin Dexter
Published: September 2020

The following study examined the association between race, ethnicity, referral source, and reasons for attrition from substance use treatment in a sample of 72,643 discharges of adolescent youth in the United States from 2014 to 2016. Black and Hispanic adolescents were more likely to be discharged due to incarceration and termination by the facility compared to White adolescents. Adolescents referred by probation, diversion, other juvenile justice organizations, health care providers, community agencies, and individual referrals were significantly more likely to be discharged due to incarceration and terminated by the treatment facility compared to youth who were referred by schools. Findings suggest that enhancing linkage to treatment from systems in the social environment may play a role in attenuating racial and ethnic disparities in rates of attrition from substance abuse treatment among adolescent youth in the United States.
Developing State Capacity: The Missing Variable for Corporate Social Responsibility?
Authors: Hira Anil
Published: September 2020

The emergence of “corporate social responsibility” (CSR) among Western multinationals reflects doubts about governments in the South to regulate production as well as a vacuum of global regulatory capacity and authority. In response to criticism, media shaming, and protests from NGOs and civil society organizations centered around labor and environmental concerns, corporations began to organize a global public regime, as reflected in the Global Compact, in the 1990s. CSR is the focus of both national and global agreements, with companies starting to work with international organizations and NGOs in emerging CSR “mixed regimes.” Yet there are inherent contradictions in both CSR and mixed regimes, ones that can only be resolved by reasserting a more activist role for the developing state.
Family Matters: Negotiating Intergenerational Mixed Identities among Eurasian Families in Singapore
Authors: Yeoh Brenda S.A. , Acedera Kristel Anne F. , Rocha Zarine L. , Rootham Esther
Published: September 2020

This paper tracks and explores the generational changes in the dynamics of racial identity and identification of Eurasians in Singapore, as reflected in family life. Eurasians are a historic mixed-descent community originating in the mixing of European and Asian cultures in the region since the 16th century. By analysing the embodied enactment and negotiation of mixed identities intergenerationally in the spheres of marriage and language choices, the paper reveals how families express and construct what it means to be Eurasian in the Singaporean context. This study draws on 30 interviews with self-identified Eurasians over two generations, including six paired intra-family interviews, illustrating intergenerational identity shifts. While the boundedness of racial identification appeared to be the norm for earlier generations, a tempering of race as a boundary marker and an openness to changing familial rhythms have served to encourage a lowering of race consciousness among younger Eurasians in Singapore.
Family and non-family sources of knowledge diversity in family firms: The role of causation logics
Authors: Randolph Robert V , Fang Hanqing ‘Chevy’ , Memili Esra , Nayir Dilek Zamantili
Published: September 2020

This article will critically analyse the sources and the role of knowledge diversity in informing causation logics in family firms. Family firms rely on knowledge resources from both intra-family and extra-family sources, which may require different approaches to effectively manage. We argue that as family firms acquire greater knowledge diversity, family-centred effectuation processes become limited and they will increasingly rely on formal causation logics to coordinate these resources. However, we expect this relationship to differ when knowledge diversity is sourced from either family or non-family sources. Empirical analyses of 242 small- and medium-sized family firms indicate that knowledge diversity positively affects a firm’s reliance on causation logics, regardless of the source of that diversity. This suggests that the affinity of family firms to leverage effectuation logics may not be characteristic of family firms in general, but instead may be an artefact of firm reliance on knowledge capital concentrated in family owners.
Hsa_circ_0003829 serves as a potential diagnostic predictor for oral squamous cell carcinoma
Authors: Zhang Hanyu , Shen Yuehong , Zhang Biru , Qian Min , Zhang Ying , Yang Hongyu
Published: September 2020

Objective

Increasing evidence suggests that circular RNAs (circRNAs) play a major role in tumorigenesis and cancer progression. This study aimed to identify aberrant expression of hsa_circ_0003829 in oral squamous cell carcinoma (OSCC) and to explore its clinical significance.

Methods

We conducted a prospective clinical study to examine the expression pattern of hsa_circ_0003829 in 60 paired OSCC and normal clinical samples and in cell lines using real-time quantitative polymerase chain reaction. We also evaluated the diagnostic value of hsa_circ_0003829 in OSCC based on receiver operating characteristic (ROC) curve analysis, and examined the relationships between hsa_circ_0003829 expression and clinicopathological features in patients with OSCC. We further used bioinformatics software CircInteractome ( https: //Circinteractome.nia.nih.gov/ ) to predict circRNA–microRNA interactions.

Results

Hsa_circ_0003829 was significantly downregulated in OSCC compared with adjacent normal tissues. The area under the ROC curve was 0.81. Low expression levels of hsa_circ_0003829 in OSCC tissues were negatively correlated with lymph node metastasis status and TNM stage.

Conclusions

Downregulated expression of has_circ_0003829 suggests that this may be a key circRNA in OSCC, and may serve as a prospective biomarker for the diagnosis of OSCC.
Hemodynamic changes following accidental infiltration of a high dose of vasopressin
Authors: Kim Jae Won , Kim Goo , Kim Tae Woo , Han Woong , Kim Mo Se , Jeong Chang Young , Park Dong Ho
Published: September 2020

Vasopressin local infiltration is useful in gynecological surgery because it can reduce hemorrhage. Depending on the activities of the sympathetic system and the renin–angiotensin system, reactions to vasopressin may differ and predicting its systemic effects is difficult. Because life-threatening complications can occur, infiltration with vasopressin should be administered with caution. A 42-year-old female patient was diagnosed with uterine leiomyomas. During a robot-assisted laparoscopic myomectomy, 50 U of vasopressin, which is ten-times the recommended dose, was accidentally infiltrated. Subsequently, bradycardia with a heart rate of 25 bpm occurred, which recovered within 3 minutes. Peripheral perfusion indices and the diameter of the radial and brachial arteries also decreased markedly and recovered within 1 hour. The surgery was concluded without additional events. The patient was discharged 2 days later with no abnormal findings. Because vasopressin infiltration can cause life-threatening complications, it is necessary to determine the extent of patient reactions to vasopressin using measures such as the peripheral perfusion index or radial and brachial artery diameters. These measures may also help to predict the occurrence of complications.
Static and free vibration analysis of functionally graded CNT reinforced sandwich plates using inverse hyperbolic shear deformation theory
Authors: Singh Surya Dev , Sahoo Rosalin
Published: September 2020

In the present study, the static and free vibration analysis of functionally graded carbon nano-tubes reinforced (FG-CNTR) sandwich plates are studied in the framework of inverse hyperbolic shear deformation theory. The governing differential equations are derived using Hamilton’s principle and solved with the Navier’s solution technique. The analytical approach is used to obtain the deflections, stresses, natural frequencies, and corresponding mode shapes of FG-CNTR sandwich plates with different material properties, stacking sequences, span thickness ratios, core to face sheet thickness ratios, and loading conditions. Different types of reinforcement distribution such as uniformly distribution (UD) and functionally graded (FG) distribution of FG-O, FG-X, FG-/\, and FG-V are considered for the analysis. Also, the efforts are made to achieve the best possible arrangement for the stacking sequences and the appropriate reinforcement distribution that will produce improved static and free vibration responses for the FG-CNTR sandwich plates.
A full-range stress-strain model for metallic materials depicting non-linear strain-hardening behavior
Authors: Swain Digendranath , Selvan S Karthigai , Thomas Binu P , Asraff Ahmedul K , Philip Jeby
Published: September 2020

Ramberg-Osgood (R-O) type stress-strain models are commonly employed during elasto-plastic analysis of metals. Recently, 2-stage and 3-stage R-O variant models have been proposed to replicate stress-strain behavior under large plastic deformation. The complexity of these models increases with the addition of each stage. Moreover, these models have considered deformation till necking only. In this paper, a simplistic multi-stage constitutive model is proposed to capture the strain-hardening non-linearity shown by metals including its post necking behavior. The constitutive parameters of the proposed stress-strain model can be determined using only elastic modulus and yield strength. 3-D digital image correlation was used as an experimental tool for measuring full-field strains on the specimens, which were subsequently utilized to obtain the material parameters. Our constitutive model is demonstrated with an aerospace-grade stainless steel AISI 321 wherein deformation response averaged over the gauge length (GL) and at a local necking zone are compared. The resulting averaged and local material parameters obtained from the proposed model provide interesting insights into the pre and post necking deformation behavior. Our constitutive model would be useful for characterizing highly ductile metals which may or may not depict non-linear strain hardening behavior including their post necking deformations.
Finger orthoses for management of joint hypermobility disorders: Relative effects on hand function and cognitive load
Authors: Jensen Anne-Mette , Andersen Joan Quist , Quisth Lena , Ramstrand Nerrolyn
Published: September 2020

Background:

Joint hypermobility refers to joints that move beyond their normal limits. Individuals with hypermobility of the fingers experience difficulties in activities of daily living. Finger orthoses are available for managing hypermobility of the fingers, but their effectiveness has received little attention in scholarly literature.

Objectives:

To determine if use of custom fit finger orthoses leads to improvements in time needed to perform standardised hand function tests, and attentional demand required to perform these tests, in individuals with joint hypermobility syndrome, Hypermobile Ehlers-Danlos syndrome or Classical Ehlers-Danlos syndrome.

Study design:

Repeated-measures study.

Methods:

Fourteen participants performed three different hand function tests (target box and block test, writing and picking up coins), with and without their finger orthoses. Time to complete each test was recorded as a measure of functional performance. Brain activity was recorded in the pre-frontal cortices as a measure of attentional demand.

Results:

Functional performance significantly improved for all but one test (picking up coins with non-dominant hand) when participants wore finger orthoses (p < 0.05). Activity in the pre-frontal cortex was lower when using the orthosis to perform the coin test (dominant hand; p < 0.05). No differences were observed in other tests (p > 0.05).

Conclusions:

Results suggested that finger orthoses improved hand function and provided limited evidence to suggest that they may also affect attentional demand. While the limited sample does not provide conclusive evidence supporting the use of finger orthosis in this clinical population, results warrant further investigation in large scale longitudinal studies or randomised controlled trials.
Analytical modeling for offshore composite rubber hose with spiral stiffeners under internal pressure
Authors: Gao Pan , Gao Qiang , An Chen , Zeng Ji
Published: September 2020

Internal pressure is the most important functional load for the offshore composite rubber hose. In this paper, the stress and radial displacement of the hose under internal pressure are investigated. The hose dimensions are length of 10.7 m and nominal bore diameter of 500 mm. The composite structure is mainly composed of cord-rubber reinforcement layers and a spiral steel stiffener. To calculate the stress and deformation of the hose, the stiffener and composite cord-rubber layers are theoretically analyzed based on the Euler–Bernoulli beam theory and the Donnell shell theory, respectively. The stiffener distinguishes the hose from common filament wound un-stiffened composite pipes in regard to the stress distribution and radial deformation. It is found that the stiffener plays an important role in affecting the mechanical behavior of composite reinforcement. Influences of the cord-winding angle, the stiffener spacing, and the stiffener’s tensile stiffness on the axial, hoop and shear stresses, and the radial displacement are investigated. The analytical model shows a good agreement with the finite element model. It is supposed to be of significant reference for practical engineering.
Impact of volatile fatty acids to alkalinity ratio and volatile solids on biogas production under thermophilic conditions
Authors: Issah Abdul-Aziz , Kabera Telesphore
Published: September 2020

The study assessed the impact of volatile fatty acids (VFA) to total alkalinity (TA) ratio (VFA/TA), and percentage volatile solids (VS) reduction of batch and semi-continuous anaerobic co-digestion of palm nut paste waste (PNPW) and anaerobic-digested rumen waste (ADRW) on digester stability and biogas production under the environmental condition of 50 ± 1°C and hydraulic retention time of 21 days for the batch studies and 14 days for semi-continuous co-digestion. The co-digestion ratios were based on percentage digester volume corresponding to 90%:10%, 75%:25% and 50%:50%. During batch and semi-continuous anaerobic co-digestion, VFA/TA of 0.32–1.0 and VS reduction of 53–67% were observed as the stable range at which biogas production was maximum. In terms of semi-continuous anaerobic digestion (AD), except for the 50%:50% ratio where biogas production progressed steadily from the first to fourteenth days, biogas production initially dropped from 180.1 to 171.3 mL between the first and third days of the 90%:10% reaching a maximum of 184 mL on the fourteenth day. Biogas production declined from 198.8 to 187.5 mL on the second day and then increased to 198.8 ± 0.5 mL in the case of the 75%:25% with a significant difference between the treatment ratios at p < 0.05. Therefore, the study can confirm that the 50%:50% ratio (PNPW:ADRW) is a suitable option for managing crude fat-based waste under thermophilic AD due to its potential for rapid start-up and complete biodegradation of active biomass within a 21-day period. This presupposes that residual methane as greenhouse gas will be void in the effluent if disposed of.
Effect of competitive adsorption on the transport of multiple pollutants through a compacted clay liner
Authors: Shu Shi , Zhu Wei , Fan Xihui , Wu Silin , Li Yunquan , Ng Charles Wang Wai
Published: September 2020

Leachate transport through municipal solid waste (MSW) landfill liners can be slowed considerably by adsorption. MSW landfill leachate contains a large variety of pollutants at very different concentrations, and there will be competitive adsorption as these pollutants are transported through the landfill’s compacted clay liner (CCL). In this study, we used batch adsorption tests and geotechnical centrifuge modelling to examine how the adsorption of pollutants commonly found in leachate changed under competitive adsorption conditions and how competitive adsorption affected the CCL breakthrough of multiple pollutants. The results showed that the adsorption of the target pollutant on clay decreased by approximately 30% when competing pollutants were added. The speed at which the pollutants were transported through a 2-m-thick CCL increased, and the breakthrough times reduced by up to 24.8%, when the competing pollutants were mixed. Competitive adsorption significantly promoted the CCL breakthrough of pollutants at low concentrations, but it had limited effect on pollutants at high concentrations.
Fatty acid profile and antioxidant status in Venus verrucosa gills as λ-cyhalothrin toxic effects
Authors: Fouzai Chaima , Trabelsi Wafa , Rabeh Imen , Bejaoui Safa , Telahigue Khaoula , El Cafsi M’hamed , Soudani Nejla
Published: September 2020

The aim of this study was to analyze the biochemical alterations in the gills of Venus verrucosa under exposure for 6 days to three doses of lambda-cyhalothrin (λ-cyh) (100, 250, and 500 µg L−1). Malondialdehyde, lipid hydroperoxide, and hydrogen peroxide levels in the gills of treated groups increased. λ-Cyh exposure significantly increased the protein carbonyl and reduced glutathione levels in the gills of all treated groups. Moreover, the activities of superoxide dismutase and glutathione peroxidase were increased. In our study, the polyunsaturated fatty acid (FA), omega-6, eicosapentaenoic acid (C20:5n-3), and docosahexaenoic acid (C22:6n-3) were increased in the treated groups. A significant decrease in the saturated FAs, omega-3, and arachidonic acid (C20:4n-6) levels was observed. The content of monounsaturated FA was changed in the groups treated with 100 and 250 µg L−1 of λ-cyh. As a corollary, desaturase and elongase activities were significantly increased. Our study provides evidence of the underlying toxic mechanism of λ-cyh and its capacity to create oxidative stress and revealed that FA profiling is a new approach for elucidating the λ-cyh toxicity.
Pups Assisting Wellness for Staff (P.A.W.S.): Evaluating the impact of canine-assisted interventions on critical care staff wellness
Authors: Caton Natasha , Campbell Kerry , Brumwell Tammy , Pratt Megan , Stewart Lisa , Wong Eliza , Zurberg Teresa
Published: September 2020

Acute care settings can expose staff to job-related stressors. Pups Assisting Wellness for Staff (P.A.W.S.) has been designed as an innovative approach to support acute care staff in the emergency department and intensive care unit. Initially, P.A.W.S. was implemented as a Comfort Dog Pilot and then expanded into a Therapy Dog Model. The Therapy Dog Model incorporated learnings from the Comfort Dog Pilot to evaluate the impact of the following: more dogs, using certified therapy dogs, and visiting at different times of the day. Results throughout the project demonstrated a positive impact on staff morale, staff stress, overall and staff satisfaction, and a strong desire for the project to continue. As a result and with a collaborative effort between a multidisciplinary team, P.A.W.S. has now been operationalized as a permanent program to support staff in acute care.
The Association of Social Support and Leisure Time Physical Activity With Mental Health Among Individuals With Cancer
Authors: Kim Jaehyun , Kim Junhyoung , Williams Ronald D. , Han Areum
Published: September 2020

Purpose:

This study examined the relationship among social support, leisure time physical activity (LTPA), and mental health among people with cancer.

Design:

Cross-sectional study.

Setting and participants:

Using the 2017 Health Information National Trends Survey, we extracted data of 504 respondents who had been diagnosed with any of the 22 types of cancer listed in the survey questionnaire.

Measures:

As independent variables, we assessed 3 different types of support: emotional, informational, and tangible support. As mediating and outcome variables, we measured LTPA and mental health, respectively.

Analysis:

Using AMOS version 22, a path analysis was conducted to measure model fit. A mediation test was then conducted using bootstrapping procedures.

Results:

The hypothesized model provided an acceptable fit to the data. Specifically, emotional support ( b = .15, p = .005), informational support ( b = .13, p = .008), tangible support ( b = .12, p = .010), and LTPA ( b = .14, p = .001) were significantly associated with mental health. We revealed a significant mediating effect of LPTA on the relationship between emotional support and mental health (Estimate = .037, 95% CI = .001–.098, p < .05).

Conclusion:

Social support and LTPA played a significant role in promoting mental health among people with cancer. In particular, the results confirmed that individuals with cancer who reported receiving emotional support tended to engage in LTPA and thus reported better mental health.
University research funding: Why does industry funding continue to be a small portion of university research, and how can we change the paradigm?
Authors: Pourdeyhimi Behnam
Published: September 2020

In the USA, the federal government is still the chief source of external funding for R&D across all industries and academia. Industry funding for universities continues to remain low. There have been many attempts to increase the interactions between industry and academia and, while there is a great deal of interest in building public–private partnerships, the results have not been promising. In this article, the author analyzes data from a number of government sources and other organizations to provide a full picture of the funding landscape in the USA. Some thought is given to why such interactions have not been successful and how we may be able to realign university activities and policies to embrace partnerships with industry.
Optimizing and characterization of Aluminium based functionally graded Silicon Nitride composite
Authors: Ambigai Rajasekaran , Prabhu Sethuramalingam
Published: September 2020

In the present study Aluminium alloy (ADC-14) reinforced with the spatial distribution of Silicon Nitride particles are fabricated through centrifugal casting. L4 orthogonal array was used to optimize the rotation speed of the mould for which two levels of 800RPM and 1200RPM was chosen. For the optimized mould speed again L4 orthogonal array was used to optimize the two factors ie. size of reinforcement and the volume fraction of Silicon Nitride. The two levels were 8% and 12% and size of reinforcement of 50microns and 100microns. Optical microscopic images were used to characterize the graded distribution of the fabricated functionally graded metal matrix composites (FGMMCs). The results show that there is an increase in hardness of 19% in the outer zone and 7% in the middle zone when compared with the inner zone ie. core of the casting. Highest hardness was obtained for the 12% reinforcement and 50microns of the reinforcement. The Regression equation and ANOVA analysis were carried out to predict the hardness and the most influencing parameter. SEM and EDS were also used to characterize the Silicon nitride reinforced FGM.
Investigation of material flow and thermomechanical behavior during friction stir welding of an AZ31B alloy for threaded and unthreaded pin geometries using computational solid mechanics simulation
Authors: Giorjao RAR , Fonseca EB , Avila JA , Monlevade EF , Tschiptschin AP
Published: September 2020

In the friction stir welding process, the tool role in the material flow and its thermomechanical behavior is still not entirely understood. Several modeling approaches attempted to explain the material and tool relationship, but to this date, insufficient results were provided in this matter. Regarding this issue and the urgent need for trustful friction stir welding models, a computational solid mechanic's model capable of simulating material flow and defect formation is presented. This model uses an Arbitrary Lagrangian-Eulerian code comparing a threaded and unthread pin profile. The model was able to reproduce the tool's torque, temperatures, and material flow along the entire process, including the underreported downward flow effect promoted by threaded pin's. A point tracking analysis revealed that threads increase the material velocity and strain rate to almost 30% compared to unthreaded conditions, promoting a temperature increment during the process, which improved the material flow and avoided filling defects. The presented results showed the model's capability to reproduce the defects observed in real welded joints, material thermomechanical characteristics and high sensitivity to welding parameters and tool geometries. Nevertheless, the outcomes of this work contribute to essential guidelines for future friction stir welding modeling and development, tool design, and defect prediction.
Analytical solutions and computational nomograms for maximum pressure angle for cam mechanisms for full and half cycloidal and harmonic motion curves
Authors: Avelar Artur Henrique de Freitas , Roschier Leif , Soares Luiza Fernandes , Ávila Pedro Henrick Salomão Oliveira
Published: September 2020

High pressure angles in cams with roller followers still pose as a problem in cam projects. The main objective of this work is to deduce the maximum pressure angle equations for full and half cycloidal and harmonic motion curves for translating roller followers in radial cams and create nomograms that can calculate this parameter by simply connecting two points by a straight line in a chart. The nomograms were made for the mentioned curves via an open source software and it is discussed the limitations of the given charts and the advantages of using the current method. Additionally, the paper reinforces the need for authors to make it clear that another well known and frequently used nomogram cannot be used as is for half curves. Although use of nomograms has fallen into disuse, it still has applications in textbooks and quick preliminary analysis in real life projects.
Modeling and multi response optimization of mechanical properties for E-glass/polyester composite using Taguchi-grey relational analysis
Authors: Kopparthi Phaneendra Kumar , Kundavarapu Vengal Rao , Kaki Venkata Rao , Pathakokila Bhaskara Rao
Published: September 2020

In the present work, E-glass/polyester composite laminates were manufactured in a customized resin transfer mould (RTM) with different layers of fiber at selected resin injection pressures. Experiments were performed employing full factorial design to study the influence of number of fiber layers and resin injection pressure on mechanical properties of the composites. Analysis of variance was implemented to study the interaction effect of process parameters on multi-responses namely tensile, flexural and impact strengths. Taguchi method based grey relational analysis was used to determine optimal control factors for the responses. Numbers of fiber layers and the injection pressure have significance with respective 73.96% and 16.57% contributions on the grey relation grades of the three responses. An optimal working condition was suggested to produce quality composite. In addition, mathematical models for the mechanical properties were also developed using the experimental results.
Application of the collision mathematical model based on a BP neural network in railway vehicles
Authors: Li Yu-Ru , Zhu Tao , Xiao Shou-Ne , Yang Bing , Yang Guang-Wu , Yuan Xiao-Lin , Tang Zhao
Published: September 2020

In order to enhance the learning performance of small-data-set models and improve the computation efficiency of finite element simulations of vehicle collision, the collision mathematical model (VCMM) based on the back-propagation (BP) neural network is established to predict the collision response data of a single car and marshalling cars at unknown velocities. The predicted results of VCMM were compared with the simulation results of the finite element method (FEM) to verify the model. The compared results show that the maximum relative errors of deformation, energy absorption and average interfacial force of a single vehicle are all below 8.5%, and the relative errors of the maximum compression of the C0 coupler and the internal energy of the A1 car among the marshalling cars are all less than 5%. In addition, the calculation time of the single car and marshalling cars collisions based on the VCMM are reduced by 24.36 and 61.8 times, respectively, compared with the FEM results, and the simulation calculation efficiency is greatly improved. The prediction result of VCMM will partially replace experimental and simulation results for crashworthiness and safety design of the vehicle structure in future studies.