bluuebunny/crossref_metadata_2025 huggingface dataset:
Composite nonlinear feedback–based adaptive integral sliding mode control for a servo position control system subject to external disturbance
Authors: Chen Hui , Xiang Min , Guan Bingjie , Sun Weijie
Published: December 2021

This paper presents a composite nonlinear feedback–based adaptive integral sliding mode controller with a reaching law (CNF-AISMRL) for fast and accurate control of a servo position control system subject to external disturbance. The proposed controller exploits the advantages of composite nonlinear feedback (CNF) and sliding mode control (SMC) schemes to improve the transient performance and increase the robustness of the closed-loop system. An integral sliding mode combined with a quick reaching law is designed to eliminate the effect of disturbances, which mitigates chattering and achieves finite-time convergence of the sliding mode. An adaptation tuning approach is utilized to deal with unknown but bounded system uncertainties and disturbances. When considering the model uncertainties and disturbances, the stability of the closed-loop system is verified based on the Lyapunov theorem. Numerical simulations are investigated to the effectiveness of the proposed scheme. The transient performance of load disk position to step signal with disturbances using CNF, composite nonlinear feedback based integral sliding mode control (CNF-ISM), and the proposed CNF-AISMRL schemes is given. The simulation results indicate that, without acquiring the knowledge of bounds on system disturbances, the proposed control scheme has superior performance in the presence of time-varying disturbances.
Characteristics and Outcomes of Parotid Gland Tumors in Adolescents
Authors: Kanetake Hirofumi , Inaka Yuko , Kinoshita Ichita , Ayani Yusuke , Ozaki Akiko , Omura Shuji , Higashino Masaaki , Terada Tetsuya , Haginomori Shin-ichi , Kawata Ryo
Published: December 2021

Objective

Parotid tumors are rare neoplasms in adults but are exceedingly infrequent in adolescents. We aimed to determine the clinical characteristics and outcomes of parotid tumors in adolescents under 20 years old.

Methods

Between 1999 and 2020, 979 cases of benign parotid tumors and 236 cases of malignant parotid tumors were treated surgically in our department. Of these, 12 benign cases (1.2%) and 9 malignant cases (3.8%) were in adolescents. There were no benign or malignant cases for those aged under 10 years.

Results

Regarding the histological type, all benign tumors were pleomorphic adenomas. About half of malignant tumors were mucoepidermoid carcinomas, and excluding one high-grade case, the grade of malignancy was all low/intermediate. The accuracy of fine-needle aspiration cytology among adolescents showed no significant difference with that of adults. In contrast to adults, adolescent benign tumor cases showed a markedly high rate of pleomorphic adenomas and no postoperative facial nerve palsy. Malignant tumors in adolescents had a different trend than adults; low/intermediate-grade malignancies were common and thus few symptoms/signs of malignancy could be observed. As well, the accuracy of fine-needle aspiration cytology was poor. All cases had a good prognosis and are disease-free survival.

Conclusion

Parotid tumors in adolescents are rare but have several characteristics that are distinct from adults. As long-term observation is required posttreatment in adolescent patients, recurrence in benign pleomorphic adenomas and poor long-term prognosis in malignant tumors, especially for those with low/intermediate-grade malignancy, are more likely to be observed.
Epithelial–myoepithelial carcinoma originating from minor salivary gland in the inferior turbinate: A case report and literature review
Authors: Li Huan , Long Yi-Lin , Wang Shi-Fei , Su Ling-Lin
Published: December 2021

Epithelial–myoepithelial carcinoma (EMC) is a rare tumor that occurs mainly in the major salivary glands. Cases occurring in the nasal cavity are rarely reported. The patient was a 48-year-old woman with a postoperative pathological diagnosis of EMC. The patient recovered well after surgery. We consulted and summarized all previous cases of nasal EMC. We also discuss the clinical presentation, treatment, and prognosis of EMC of the nasal cavity and paranasal sinuses.
Spurious Correlation Due to Scaling
Authors: Glasscock Robson , Korenok Oleg , Dorminey Jack
Published: December 2021

Scaling is common in empirical accounting research. It is often done to mitigate heteroscedasticity or the influence of firm size on parameter estimates. However, Barth and Clinch conclude that common diagnostic tools are ineffective in detecting various scale effects. Using analytic results and Monte Carlo simulations, we show that common forms of scaling, when misapplied, induce substantial spurious correlation via biased parameter estimates. Researchers, when uncertain about the exact functional form of scale effect, are typically better off dealing with both heteroscedasticity and the influence of larger firms using techniques other than scaling.
Parents’ Perceptions of Education and Culture as a Context of Parental Stress: A Study of Parents of Preschool Children in Hong Kong
Authors: Guo Hua , Chiu Stephen Wing Kai
Published: December 2021

This study examines how cultural context mediates the association between parents’ perceptions of education and parental stress under the ABC-X model. The analysis was based on a sample of 6454 parents of preschool children in Hong Kong. Exploratory and confirmatory factor analysis detected two major dimensions of parents’ perceptions of children’s education. Ordinary least squares regression models with interaction terms were used to analyze the identified dimensions’ associations with parental stress. The study found preschool parents with an assertive perception of children’s cognitive skills, discipline, coercion, and competition were more stressed than parents with a responsive perception of children’s non-cognitive skills, self-management, autonomy, and cooperation in education. Parents paradoxically caught between these two types of perceptions were the most stressed. Native residents and earlier immigrant parents also had a higher level of stress than recent immigrants.
Family Context Surrounding the Use of Technologies and Their Impact in Adolescents’ Media Multitasking
Authors: Pousada Modesta , Malo Sara , Viñas Ferran , Martín-Perpiñá Mercedes , Gómez-Zúñiga Beni
Published: December 2021

Recent studies pointed out that practically all adolescents are regular users of information and communications technology (ICT). Since the most usual context for the use of technology is the home, our aim is, on the one hand, to characterize the family technology context among adolescents aged between 11 and 18 years and, on the other hand, to analyse the relationship between multitasking and the different variables found within this family context. Participants were 977 adolescents. Significant relationship between the number of devices in the home and the frequency with which these are used are showed. Although a 60% of the adolescents have no parental rules over this use, there does not appear to be any relationship between the existence, or lack thereof, of rules over the use of ICT and multitasking. To reduce adolescents amount of media multitasking, we would recommend having fewer devices in the home rather than imposing rules about their use.
Child–Parent Relationships and Older Adults’ Health: A Cross-Cultural Comparison Between China and the United States
Authors: Lu Peiyi , Kong Dexia , Shelley Mack
Published: December 2021

This study compared the associations of child–parent relationships with older adults’ multidimensional health in the United States and China. Two waves of data from the US Health and Retirement Study and its sister study in China (2012–2015) were used (2174 non-Hispanic [NH] White Americans and 4467 Chinese). Linear regression models were conducted for cross-sectional and longitudinal comparisons. Results showed most child–parent relationships had nonsignificant associations with NH White Americans’ health. In contrast, closer child–parent relationships were linked to fewer depressive symptoms and better cognitive function among Chinese. Co-residence was associated with poorer health among older Chinese. Over a 2-year period, living nearby was linked to poorer cognitive function among NH White Americans and fewer depressive symptoms among Chinese. Having weekly contact was predictive of better cognition among Chinese. This study revealed cross-cultural differences in the associations between child–parent relationships and older adults’ health. Family relationships in accordance with Chinese culture could improve health.
Women Caregivers Under the Spanish Autonomy and Dependence System: A New Social Underclass?
Authors: Martínez-López José Ángel , Solano Lucas Juan Carlos , Frutos Balibrea Lola , Bote Díaz Marcos
Published: December 2021

Long-term care in Spain has traditionally been provided by women as consequence of a family welfare system based historically on familism and sexual division of labour. The Autonomy and Dependence Law, passed in 2006, involved the regulation by the State of informal care. However, the economic crisis is maintaining and stressing gender differences in relation to care since a new profile of women is being built: poor caregivers, as a specific group responsible for the provision of care, becoming an ‘internal market’ linked to the application of the so called Dependence Law. This study presents an analysis of key secondary sources from the System of Autonomy and Attention to Dependency, the Unemployment System and the most relevant indicators of poverty and social exclusion. In addition, an ad hoc survey and semi-structured interviews were conducted. 55.2% of caregivers are poor women, inactive or unemployed and use the cash-for-care as basic income.
Including Surgical Resection in the Multimodal Management of Very Locally Advanced Sinonasal Cancer
Authors: Karp Jerome M. , Hu Kenneth S. , Persky Michael , Persky Mark , Jacobson Adam , Tran Theresa , Li Zujun , Givi Babak , Tam Moses M.
Published: December 2021

Objective

Sinonasal cancer often presents as locoregionally advanced disease. National guidelines recommend management of stage T4b tumors with systemic therapy and radiotherapy, but recent studies suggest that including surgical resection in the multimodal treatment of these tumors may improve local control and survival. We queried the National Cancer Database to examine patterns of care and outcomes in T4b sinonasal squamous cell carcinoma (SCC).

Study Design

Prospectively gathered data.

Setting

National Cancer Database.

Methods

Patients with T4b N0‐3 M0 sinonasal squamous cell carcinoma diagnosed in 2004 to 2016 were stratified between those who received chemoradiotherapy and those who underwent surgical resection with neoadjuvant or adjuvant treatment. The overall survival of each cohort was assessed via Kaplan‐Meier analysis and Cox proportional hazard models, with repeat analysis after reweighting of data via inverse probability of treatment weighting.

Results

Among 805 patients included in analysis, 2‐year overall survival for patients undergoing surgical resection was 60.8% (95% CI, 56.1%‐65.9%), while for patients undergoing chemoradiotherapy it was 46.7% (95% CI, 41.9%‐52.0%). On Cox regression analysis, the inclusion of surgery in management was associated with improved survival in univariate analysis (hazard ratio [HR], 0.723 [95% CI, 0.606‐0.862]; P <. 001) and multivariate analysis (HR, 0.739 [95% CI, 0.618‐0.885]; P =. 001). Results with reweighted data were consistent in univariate analysis (HR, 0.765 [95% CI, 0.636‐0.920]; P =. 004]).

Conclusion

Surgical treatment with neoadjuvant or adjuvant treatment for stage T4b sinonasal SCC was associated with promising survival outcomes, suggesting a role for incorporating surgery in treatment of select T4b SCC, particularly when removal of all macroscopic disease is feasible.
Co-creating rehabilitation: Findings from a pilot and implications for wider public service reform
Authors: Baines Susan , Fox Chris , Harrison Jordan , Smith Andrew , Marsh Caroline
Published: December 2021

As part of a large pan-European project on co-creating public services we supported the design of a programme in England that attempted to operationalise research on desistance, through a model of co-created, strengths-based working. We then evaluated its implementation and impact. The programme was implemented in a Community Rehabilitation Company. It was delivered in the context of rapid organisational change, often in response to rapidly changing external events and a turbulent policy environment. These factors impeded implementation. An impact evaluation did not identify a statistically significant difference in re-offending rates between the intervention group and a comparator group. However, in-depth qualitative evaluation identified positive examples of co-production and co-creation, with individual case managers and service users supportive and noting positive change. Taken as a whole our findings suggest that a co-created, strengths-based model of probation case management is promising but needs to be accompanied by wider systems change if it is to be embedded successfully.
Women’s pains of punishment: Experiences of female offenders serving community sentences in Lithuania
Authors: Nikartas Simonas , Tereškinas Artūras
Published: December 2021

Using the concept of ‘pains of punishment’, the article analyses the experiences of Lithuanian women serving community sentences. Our study demonstrates that women experience the universal pains of punishment associated with stigmatisation, shame, and the inconveniences caused by punishment, as well as constraints and anxieties about impending imprisonment. Furthermore, the complex context of their social environment (relationships with partners, children, and other loved ones) contributes to these pains. In contrast to some previous studies, the Lithuanian women’s experiences do not fall under the category of ‘demanding clients’ since the research participants do not think of the Probation Service as an institution that could meet their needs and provide them with assistance.
A modified perfusion protocol for pulmonary endarterectomy in a patient with a hematologic malignancy treated with a tyrosine kinase inhibitor
Authors: Haumann Renard G , Buys Dedré , Hofland Eline , Romijn Hans WA , Kamminga Suzanne K , Aman Jurjan , Nossent Esther J , Symersky Petr
Published: December 2021

Tyrosine kinase inhibitors (TKI) are known to be highly effective in the treatment of various cancers with kinase-domain mutations such as chronic myelogenous leukemia. However, they have important side effects such as increased vascular permeability and pulmonary hypertension. In patients undergoing pulmonary endarterectomy with deep hypothermic circulatory arrest, these side effects may exacerbate postoperative complications such as reperfusion edema and persistent pulmonary hypertension. We report on a simple modification of the perfusion strategy to increase intravascular oncotic pressure by retrograde autologous priming and the addition of packed cells and albumin in a patient treated with a TKI.
The physiology of extracorporeal membrane oxygenation: The Fick principle
Authors: Lim Hoong
Published: December 2021

Extracorporeal membrane oxygenation (ECMO) can be delivered in veno-arterial (VA) and veno-venous (VV) configurations based on the cannulation strategy. VA and VV ECMO are delivered primarily for haemodynamic and respiratory support in patients with severe heart and lung failure, respectively. The Fick principle describes the relationship between blood flow and oxygen consumption – key parameters in the physiological management of extracorporeal support. This review will discuss the application of the Fick principle in: (i) recirculation in VV ECMO; (ii) the quantification of oxygen delivery (DO2) in VV ECMO and (iii) the quantification of transpulmonary blood flow and systemic arterial oxygen saturation in VA ECMO.
Investigating Affective Responding to Daily Positive Events Among Adolescents Using Ecological Momentary Assessment
Authors: Chun Sarah K. , Benjamin Katherine S. , Mezulis Amy H.
Published: December 2021

The experience of positive events is associated with increased positive affect, which can beneficially impact the physical and mental health outcomes of adolescents. Despite an increase in important life events during adolescence, little research has examined the influence of positive events on affect in this population. This study used Ecological Momentary Assessment to investigate individual differences in the effects of daily positive events on momentary positive and negative affect and event-specific positive affect among 136 adolescents ( M age = 13.03 years). Results indicated that interpersonal and independent events elicited greater event-specific positive affect than non-interpersonal and dependent events. Dependent interpersonal events were associated with the greatest positive affect compared to other combinations of event types. Gender did not moderate these effects. These findings may address the gap in the literature regarding the types of daily positive events that elicit the most positive affect in adolescents, and in turn, may enhance well-being.
Intra- and extra-capsular ganglia at the gastrocnemius origin and association with meniscal tears and severity of osteoarthritis of the knee joint
Authors: Choi Jin Young , Park Hee Jin , Kim Ji Na , Kim Myung Sub , Choi Yoon Jung , Shin Hun Kyu , Son Eun Seok
Published: December 2021

Background

The association between size of ganglia or type of ganglia (intra-articular or extra-articular) and meniscal tears or severity of the osteoarthritis (OA) is not evaluated.

Purpose

To evaluate the prevalence, size, and location of intra- and extra-capsular ganglia at the gastrocnemius origin and to assess their associations with meniscal injury and grades of OA.

Material and Methods

This study included 301 consecutive patients who had knee pain and had undergone magnetic resonance imaging (MRI) of the knee. We evaluated presence of ganglia at the gastrocnemius muscle origin site and diagnosed whether it was an intra-capsular located or mixed-capsular located (intra-capsular and extra-capsular) and then measured the diameter of each ganglion. After two weeks, we evaluated whether articular cartilage injury existed. The presence of a meniscal tear was also recorded.

Results

A total of 186 patients (93%) had intra- and extra-capsular ganglia. Intra-capsular ganglia were found in 183 cases (91%) and mixed-capsular ganglia were found in 16 cases (8%). In cases with intra- and extra-capsular ganglia, more meniscal tears were found ( P = 0.029). Intra-capsular ganglia showed more meniscal tears ( P = 0.021). Intra-capsular ganglia were more likely to have high-grade OA ( P = 0.043). Patients who had a meniscal tear displayed larger-sized ganglia, especially of the intra-capsular type ( P = 0.044).

Conclusion

Patients with intra- and extra-capsular ganglia, especially of the intra-capsular type, are more likely to have meniscal injury and more severe OA. Patients with a meniscal tear or OA are more likely to have larger intra- and extra-capsular ganglia, especially of the intra-capsular type.
Supplier-dedicated resources and flexibility’s roles in a manufacturer’s superior performance
Authors: Jin Yan , Norbis Mario , Awudu Iddrisu
Published: December 2021

In today’s ever-changing environment, a manufacturing firm depends increasingly on suppliers to sustain its competitiveness. The recent COVID-19 pandemic has demonstrated that supply chain disruptions impair a firm’s ability to deliver customer value. The adverse effect is more significant when the supply chains in question are inflexible rather than flexible. This research argues that supplier-dedicated resources (SRs) and supplier flexibility (SF) determine a manufacturing firm’s competitive advantage (CA) and provide a comprehensive view of these supply chain-based factors in the same model. Based on data from 201 respondents in US manufacturing firms that vary in industry type and company size, the results confirm that SRs are critically extended resources for a manufacturing firm. The results also demonstrate that SF mediates the effect of SRs on a manufacturer’s sustainable CA fully. Further, the research develops and verifies SRs as a second-order construct reflecting the synergistic benefit of three subconstructs: dedicated technology, engineers and managers, and company climate.
HR factors for the successful implementation of Industry 4.0: A systematic literature review
Authors: Verma Anju , Venkatesan Murugesan
Published: December 2021

As the world moves deeper into the fourth industrial revolution, organizations around the world are polarizing towards the transformation and adoption of the advanced technologies of Industry 4.0. However, recent studies suggest that organizations struggle and face several managerial challenges in their implementation. As a consequence, many studies examined the potential factors that can influence Industry 4.0 implementation. Based on a systematic literature review, this study has tried to explore, examine, and synthesize the potential human resource (HR) success factors and develop an efficient Industry 4.0 HR framework that can play a vital role in Industry 4.0 implementation. This study would also build a solid foundation for practitioners, academicians, and researchers to get a better understanding of the impact of Industry 4.0 on HR management.
SMEs’ financial risks in supply chain trade with large companies: The case of Italian automotive component industry
Authors: Errico Marco , De Noni Ivan , Teodori Claudio
Published: December 2021

Becoming a supplier of large companies is traditionally considered to be positive for small and medium enterprises’ (SMEs) competitiveness. Small businesses can take several advantages by joining supply chain trade with large companies such as scale efficiency and productivity as well as technological and managerial abilities, product and process innovation, market positioning, and reputation. However, not everything is convenient per se. The subcontracting by large companies might provide some financial criticalities that need to be faced and properly managed by SMEs to exploit supply chain benefits without affecting financial stability and losing competitiveness. In this direction, the literature on supply chain finance has recently focused on financial issues related to working capital optimization in terms of accounts payable, receivable, and inventories. Adopting this perspective, the study contributes to a better understanding of SMEs’ financial constraints in supply chains driven by large companies by investigating a sample of small Italian firms, which operate in the metal casting industry and by comparing firms joining and not joining the automotive supply chain.
Writing economies and economies of writing
Authors: Dufty-Jones Rae , Gibson Chris , Barnes Trevor
Published: December 2021

Our introduction to the Exchanges section unpacks the two terms, writing economies and economies of writing, as well as previewing the subsequent nine papers included within the section. We contend first, that the economy cannot exist until it is first written about – ‘writing economies’. Here a variety of dates have been suggested as to its first written representation, from roughly 2500 hundred years ago to a mere hundred years. Second, we argue that the pressures on academics to write – ‘economies of writing’ – have never been more acute than now and bound up with the neoliberalization of the university.
Aggressive Script Rehearsal in Adult Offenders: Characteristics and Association With Self-Reported Aggression
Authors: Hosie Julia , Dunne Ashley , Simpson Katrina , Daffern Michael
Published: December 2021

This study explored the frequency, recency, content, severity, and targets of aggressive scripts reported by 94 incarcerated Australian males. The scripts of participants who reported a history of repeated and severe aggression were compared with the scripts of participants who reported a history of less severe and less frequent aggression. As hypothesized, participants with a history of more frequent and severe aggressive behavior reported more severe aggressive script content and more frequent script rehearsal. Furthermore, participants with a history of more frequent and severe aggressive behavior reported feelings of anticipation and excitement when they rehearsed aggressive scripts as well as an increase in the severity of aggressive scripts rehearsed over time. These results have important implications for risk assessment and treatment of violent offenders.
Volunteers: An Effective Medium for Delivering Therapeutic Lifestyle Interventions
Authors: Kent Lillian M. , Rankin Paul M. , Morton Darren P. , Rankin Rebekah M. , Greenlaw Roger L. , Englert Heine S.
Published: December 2021

Purpose

Lifestyle modification programs have been shown to effectively treat chronic disease. The Coronary Health Improvement Program has been delivered by both paid professional and unpaid volunteer facilitators. This study compared participant outcomes of each mode in the United States.

Design

Pre-/post-analysis of CHIP interventions delivered between 1999 and 2012.

Setting

Professional-delivered programs in Rockford Illinois 1999-2004 and volunteer-delivered programs across North America 2005-2012.

Subjects

Adults ≥21 years (professional programs N = 3158 34.3% men, mean age = 54.0 ± 11.4 years; volunteer programs N = 7115 33.4% men, mean age = 57.4 ± 13.0 years).

Measures

Body mass index, blood pressure (systolic and diastolic), blood lipid profile (total cholesterol, high-density lipoprotein, triglycerides, low-density lipoprotein), and fasting plasma glucose.

Analysis

Analysis of Covariance, with adjustment for age, gender, BMI change and baseline biometric and effect sizes.

Results

The professional-delivered programs achieved significantly greater reductions in BMI (.4%, P < .001) and HDL (1.9%, P < .001) and the volunteer-delivered programs achieved greater reductions in SBP (1.4%, P < .001), DBP (1.1%, P < .001), TC (1.4%, P = .004), LDL (2.3%, P < .001), TG (4.0%, P = .006), and FPG (2.7%, P < .001). However, the effect size differences between the groups were minimal (Cohen’s d .1-.2).

Conclusions

Lifestyle modification programs have been shown to effectively treat chronic disease. The Complete Health Improvement Program (CHIP) lifestyle intervention has been delivered by both paid professional and unpaid volunteer facilitators. This study compared selected chronic disease biometric outcomes of participants in each mode in the United States. It found volunteer-delivered programs do not appear to be any less effective than programs delivered by paid professionals, which is noteworthy as volunteers may provide important social capital in the combat of chronic disease.
Education in Post-Soviet Russia: Marketisation, Financialisation and Bureacratisation – The Case of Universities
Authors: Yakovleva Natalia
Published: December 2021

Since the dissolution of the Soviet Union, market relations and institutions have begun vigorously penetrating not only the fields of production and services, but also the social sphere. In this text, the author reveals the contradictions implicit in the transformations that over 30 years have occurred in post-Soviet Russia in the field of education and that have seen the total marketisation of this area. As an example, the article examines Russian universities. The process of marketisation of university education has taken the direct forms of the establishment of private universities and the introduction of paid tuition in state universities, and also of changes to the administrative structures of universities, to the content of instruction programmes, and to assessment of the quality of the education received by students as well as of the outcomes of the activity both of university teachers and of the institutions as a whole.
Onset of Transient Sadness Following the Concomitant Use of a Triptan and Selective Serotonin Reuptake Inhibitor/Serotonin Norepinephrine Reuptake Inhibitors Therapy: A Case Report
Authors: Meng Yuki , Yuen Jamie
Published: December 2021

Background: Migraine and depression have a bi-directional, positive association. The likelihood of these conditions being comorbidities is high, thus, the possibility of concomitant use of an antidepressant and a triptan is also increased. Case Presentation: We present a case of a 39-year-old female with a history of migraine with aura and depression who had brief episodes of exacerbated depressive symptoms following oral administration of sumatriptan 100 mg daily as needed while taking various selective serotonin reuptake inhibitor (SSRI) and serotonin and norepinephrine reuptake inhibitor (SNRI) medications on different occasions. The patient experienced 30-minute episodes of sweating and subjective increase in temperature approximately 2–3 hours after administration of sumatriptan 100 mg. This was followed by a transient exacerbation of sadness described by the patient as unhappiness, hopelessness, and tearfulness, which lasted 1 to 2 hours. To date, there are no other published case reports that have described this particular presentation. Several studies have reported possible serotonin syndrome as a result of the combination. Current evidence and known pharmacological actions of SSRIs/SNRIs and triptans are not well-defined enough to explain how one can experience episodic worsening depression. Conclusion: This case illustrates that clinicians should consider other potential adverse effects of the combined use of triptans and SSRIs/SNRIs beyond serotonin syndrome.
Evolving Crisis and Changing Networks: NGOs’ Stakeholder Engagement on the Global Refugee Crisis
Authors: Sun Jingyi , Yang Aimei , Saffer Adam J.
Published: December 2021

Nongovernmental organizations (NGOs) increasingly utilize social media for strategic stakeholder engagement. This study proposes a network-oriented theoretical framework to understand how NGOs’ engagement with complex networks of stakeholders on the global refugee issue varies as the issue moves from low to high public attention stages. We draw from research on multistakeholder issue networks and issue niche theory and analyze a large-scale Twitter data set containing tweets from hundreds of organizations from more than 30 countries. This cross-national, longitudinal study tracks issue evolution and NGOs’ tie formation patterns among themselves and with complex stakeholders (i.e., government and media) as public attention to the refugee issue increases. The results of our exponential random graph models (ERGMs) show how cross-sector stakeholders interact dynamically and how different issue identities position NGOs uniquely in issue niches as the issue evolves. We also find that organizations’ country-level homophily influences tie formation. Theoretical and practical implications are discussed.
Students’ perceptions of the entrepreneurial culture in Finnish higher education institutions
Authors: Lahikainen Katja , Peltonen Kati , Oikkonen Elena , Pihkala Timo
Published: December 2021

The purpose of this study is to add to the literature on entrepreneurial universities by investigating entrepreneurial culture (EC) in higher education institutions (HEIs). The authors investigate how students experience EC and which factors explain their perceptions of EC. The study is based on a survey of HEI students in Finland with 1277 responses. The results show that formal institutional support and institution-level activities have the strongest impact on the students’ experienced EC. According to the findings, formal institutional support has a greater impact on students’ perceptions of EC than student-driven activities. Furthermore, the results highlight that the encouragement of teachers has a greater influence on students’ perceptions of EC than peer students and student-driven activities. Accordingly, the paper’s theoretical contribution to the literature lies in its demonstration that institutional support, in addition to the encouragement of teachers, influences HEI students’ perceptions of EC. With regard to practical implications, the findings indicate that, if HEIs wish to build an EC and operate entrepreneurially, it is vital to support teachers’ entrepreneurial behaviour and thinking. In addition, equal emphasis needs to be placed on the observable artefacts and on clear, well-communicated organisational structures and processes.
Electromagnetic interference shielding effectiveness of polypyrrole-silver nanocomposite films on silane-modified flexible sheet
Authors: Benzaoui Karim , Ales Achour , Mekki Ahmed , Zaoui Abdelhalim , Bouaouina Boudjemaa , Singh Ajay , Mehelli Oussama , Derradji Mehdi
Published: December 2021

The conventional electromagnetic interference (EMI) shielding materials are being gradually replaced by a new generation of supported conducting polymer composites (CPC) films due to their many advantages. This work presents a contribution on the effects of silane surface–modified flexible polypyrrole-silver nanocomposite films on the electromagnetic interference shielding effectiveness (EMI-SE). Thus, the UV-polymerization was used to in-situ deposit the PPy-Ag on the biaxial oriented polyethylene terephthalate (BOPET) flexible substrates whose surfaces were treated by 3-aminopropyltrimethoxysilane (APTMS). X-ray Photoelectron Spectroscopy (XPS) analyzes confirmed the APTMS grafting procedure. Structural, morphological, thermal, and electrical characteristics of the prepared films were correlated to the effect of substrate surface treatment. Thereafter, EMI-SE measurements of the elaborated films were carried out as per ASTM D4935 standard for a wide frequency band extending from 50 MHz to 18 GHz. The obtained results confirmed that the APTMS-treated BOPET film exhibit higher EMI shielding performance and better electrical characteristics compared to the untreated film. In fact, a 32% enhancement of EMI-SE was noted for the treated films compared to the untreated ones. Overall, these results put forward the role played by the surface treatment in strengthening the position of flexible PPy-Ag supported films as high-performance materials in electronic devices and electromagnetic interference shielding applications.
Parametric analysis of topologically optimized mechanical member considering dynamic loading
Authors: Lakshmi Srinivas G , Javed Arshad
Published: December 2021

The optimal topology and its performance in dynamic loading situations result in discontinue function corresponding to the input factors such as volume fraction, thickness, material property, and loading conditions. In a realist scenario, the performance prediction becomes erroneous and challenging for the components under dynamic loading conditions with uncertainties. The conventional closed-form deterministic approaches are complicated for these problems. Here, a method is presented to establish the relative influence and function relationship of the input factors with the performance values, including controllable and non-controllable uncertainties. The design of experiment approach is used to apply full factorial design with Taguchi’s orthogonal array; performances of the optimal topologies are considered responses. The non-uniform topology generation method is applied based on the deflection threshold value to generate topologies for dynamic conditions. A dynamic model of the manipulator-link is developed to apply boundary conditions and provide performance values: compliance, deflection, Stress, and energy consumption values. Statistical techniques such as the analysis-of-mean (ANOM), analysis-of-variance (ANOVA), signal-to-noise-ratio (SNR), and mean performance values are employed to observe the significance of input factors and generate equivalent preformation relation. From ANOM and ANOVA, all input parameters show mutual interaction; force is observed as the most significant factor. From SNR values, experimental combination number 9,9,6,1 is observed as the most robust for compliance (21.13), deflection (43.93), Stress (−16.64), and energy consumption (12.05). Similarly, at the same combinations, the mean performance values are minimum and coefficient of determination (R2) percentages of the model are 94.64%, 96.93%, 73.69%, and 95.14%.
Dynamic research and experimental analysis of a longitudinal–torsional coupled impactor
Authors: Tian Jialin , Deng Zhe , He Hongzhi
Published: December 2021

The rock breaking efficiency of drill bit is deeply affected with the increase of drilling depth. The increase length of the drill string leads to torsional stiffness decrease, which may even result in the stick-slip phenomena. In order to improve the rock breaking efficiency and reduce the stick-slip, this paper proposed a longitudinal–torsional coupled impactor. The internal working mechanism was carried out by theoretical analysis and experimental test. Moreover, comparing the computation and test results, the following conclusions can be obtained and verified. This innovative design can provide appropriate longitudinal-torsional coupled impact to drill bit during drilling process, and the movement of the hammer and pendulum is periodic. With the increasing flow rate of drilling fluid, this tool can generate corresponding larger impact force, torque and higher impact frequency. The theoretical analysis results are consistent with the experimental test results, which verify the reliability of the innovative design and the accuracy of theoretical analysis. This paper can provide reference for the innovative design of downhole drilling tool, the development of drilling dynamics and the improvement of drilling efficiency especially in the conditions of complex and ultra-deep wells.
Machining parametric study on the natural fiber reinforced composites: A review
Authors: Mahakur Vijay Kumar , Bhowmik Sumit , Patowari Promod Kumar
Published: December 2021

Nowadays, the utilization of natural fiber reinforced composite has increased frequently. These natural fibers have significant features like low cost, renewable, and, more importantly, biodegradable in nature, making them to be utilized for various industrial sectors. However, the massive demand for natural fiber reinforced composites (NFRC), forces them to be machined and operated, which is required for countless areas in multiple industries like automotive, marine, aerospace and constructions. But before obtaining the final shape of any specimen, this specimen should come across numerous machining processes to get the desired shape and structure. Therefore, the present review paper focused on the various aspects during conventional and unconventional machining of the NFRC. It covers the work by exploring the influence of all input variables on the outcome produced after machining the NFRC. Various methodologies and tools are also discussed in this article for reducing the machining defects. The machining of the NFRC is found as a challenging task due to insufficient interlocking between the matrix and fibers, and minimum knowledge in machining characteristics and appropriate input parameters. Thus, this review is trying to assist the readers to grasp a basic understanding and information during the machining of the NFRC in every aspect.
Fluid relaxation and retardation time properties in the flow of Burgers fluid subject to modified heat and mass flux theory
Authors: Iqbal Zahoor , Ahmed Awais , Anwar Amina , Sivasankaran Sivanandam , Alshomrani Ali Saleh , Khan Masood
Published: December 2021

In this study, the heat transport is scrutinized in the flow of magnetized Burgers fluid accelerated by stretching cylinder. Rather than, classical Fourier's and Fick's laws, the Cattaneo-Christov theory featuring the improved heat and mass conduction is utilized to investigate the energy transport. Further, the transport of thermal and solutal energy is controlled by the significant influence of heat generation/absorption and chemical reaction. The physical flow problem is modelled in the form of partial differential equations (PDEs) which are then transformed into the non-linear ordinary differential equations (ODEs) by invoking appropriate similarity variables. The numerical simulation to the system of ODE's is tackled by employing BVP-Midrich scheme in Maple. The numerical results for flow field, thermal and concentration distributions are exhibited graphically. The impact of fluid relaxation and retardation time parameters on the velocity field are observed in growing and decaying way, respectively. Both the thermal and solutal energy transport decline with higher values of retardation time parameter. The rise in Burgers fluid parameter enhances the transport of energy during the fluid motion. The effect of thermal and solutal relaxation time parameters on heat and mass transport in the fluid are noticed in the declining manner.
Research on rolling stability of the flexible waverider based on computational fluid dynamics/computational structural dynamics/rigid body dynamics coupling methodology
Authors: Yiming Shang , Ruhao Hua , Xianxu Yuan , Zhigong Tang , Zhongwei Wang
Published: December 2021

The shape of hypersonic aircrafts represented by waveriders is becoming more slender and flatter, thereby greatly reducing the structural rigidity. This innovation is applied to satisfy the demand of long-range flight. The rolling stability of the waveriders is poor due to the slender shape. Therefore, the effect of the elastic deformation on the rolling stability cannot be ignored. The effect of the elastic deformation on the stability of rolling and forced pitching/free rolling coupling motions of the waveriders is studied through computational fluid dynamics (CFD)/computational structural dynamics (CSD)/rigid body dynamics (RBD) coupling methodology. Comparison results of numerical simulation indicate that the elastic deformation of the structure increases the local angle of attack, thereby enhancing the static stability of the waveriders. The rolling motion of the waveriders changes from point attractor to periodic attractor when the vibration velocity due to elastic deformation is considered. The rolling oscillation frequency of the flexible model is higher than that of the rigid model. For the forced pitching/free rolling motion, stability theory based on the rigid body hypothesis is unsuitable when the elastic effect is taken into consideration.
Recent advances in active fault tolerant flight control systems
Authors: Raja Muhammad Sohail Khan , Ali Qasim
Published: December 2021

The Flight Control System (FCS) is considered as the brain of an aerial vehicle. It is a mechanism through which pilot’s commands are transferred to the actuators of the aircraft control surfaces. In order to ensure safety and increase reliability of aerial vehicles, development of fault tolerant FCSs has been the focus of research community for past few decades. Fault tolerant ability enables an aircraft to maintain satisfactory performance even in the state of a fault. Fault Tolerant Control Systems (FTCS) are categorized as passive and active control systems. Passive FTCS are designed to mitigate the effects of certain known faults. These faults can be related to sensor failure, actuator failure, or system component failure. On the other hand, active FTCS contain a controller reconfiguration mechanism, whereby, they can adjust the controller input online to mitigate the effects of the faults. In this way, they can accommodate complicated and versatile faults as compared to their passive counterparts. This paper presents a review of significant research during last decade in active fault tolerant control with applications to FCSs. A review of state-of-the-art works in this domain has also been presented. Upon review, these state-of-the-art research interests have been categorized into respective categories. Furthermore, research works have been cataloged based on their technology readiness levels. Based on these reviews, future research directions have also been highlighted.
Design of tension structures and shells using the Airy stress function
Authors: Sehlström Alexander , Olsson Karl-Gunnar , Williams Chris JK
Published: December 2021

Discontinuities in the Airy stress function for in-plane stress analysis represent forces and moments in connected one-dimensional elements. We expand this representation to curved membrane-action structures, such as shells and cable nets, and graphically visualise the internal stresses and section forces at the boundary necessary for equilibrium. The approach enhances understanding of the interplay between form and forces and can support design decisions related to form-finding and force efficiency. As illustrative examples, the prestressing needed for three existing cable nets is determined, and its influence on the edge-beam bending moment is explored.
The Peace of God
Authors: Young Andrew
Published: December 2021

Scholars have argued that the politically fractured landscape of medieval Western Europe was foundational to the evolution of constitutionalism and rule of law. In making this argument, Salter and Young (2019) have recently emphasized that the constellation of political property rights in the High Middle Ages was polycentric and hierarchical; holders of those rights were residual claimants to the returns on their governance and sovereign. The latter characteristics—residual claimancy and sovereignty—imply a clear delineation of jurisdictional boundaries and their integrity. However, historians’ description of the “feudal anarchy” that followed the tenth-century disintegration of the Carolingian Empire does not suggest clearly delineated and stable boundaries. In this paper, I highlight the role of the Peace of God movement in the 11th and 12th centuries in delineating and stabilizing the structure of political property rights. In terms of historical political economy, the Peace of God movement provides an important link between the early medieval era and the constitutional arrangements of the High Middle Ages.
Sleep Disturbance and Self-management in Adults With Subarachnoid Hemorrhage: A Qualitative Study
Authors: Byun Eeeseung , McCurry Susan M. , Kim Boeun , Kwon Suyoung , Thompson Hilaire J.
Published: December 2021

Subarachnoid hemorrhage (SAH) survivors often experience sleep disturbances. Little is known about sleep-management practices used to improve their sleep. The purpose of this qualitative study was to explore interest in and engagement with self-management practices to promote sleep health in SAH survivors. We conducted a cross-sectional qualitative study using semi-structured interviews with a convenience sample of 30 SAH survivors recruited from a university hospital. We conducted content analysis of interview transcripts. Three themes and 15 subcategories were identified: (1) sleep disturbances (difficulties falling asleep, wake after sleep onset, daytime sleepiness, too much or insufficient sleep, and poor sleep quality); (2) sleep-management practices (exercise, regular sleep schedule, relaxation, keeping busy and staying active, changing beverage intake, taking supplements, taking medications, recharging energy, and barriers to sleep management); and (3) consulting with healthcare providers (discussing sleep problems with healthcare providers). Self-management strategies focusing on health-promoting behaviors may improve SAH survivors’ sleep health.