bluuebunny/crossref_metadata_2025 huggingface dataset:
Malicious and benign maternal envy in Chinese childrearing
Authors: Zong Wenqing , Hawk Skyler T.
Published: May 2021

Mothers utilize social comparisons to other parents to calibrate evaluations of themselves and their children, and these comparisons might prompt feelings of envy. Envy can either be malicious and destructive, or relatively more benign and constructive. This research examined distinctions between malicious and benign envy among Chinese mothers, differences from related emotions (i.e., resentment and admiration), and themes present in these experiences. An online sample of 152 Mainland Chinese mothers ( Mage = 46.91, SD = 2.26) recalled malicious and benign envy, admiration, and resentment experiences toward other parents and reported associated appraisals, motivations, and action tendencies. Results showed distinctions between malicious and benign maternal envy. Malicious envy included lower perceived control, higher perceived unfairness, and more desire to degrade the other than benign envy. Benevolent feelings toward the envied target characterized benign envy. Both forms of envy were linked to self-improvement motivation. Personal characteristics and achievements of both other parents and other children were prominent themes in mothers’ experiences of various emotions. This research provides insights into how and why Chinese mothers experience different forms of envy, and has implications for research on social comparisons made in parenting contexts.
Gendered dispossession and women’s changing poverty by slum/squatter redevelopment projects: A case study from Turkey
Authors: Borsuk Imren
Published: May 2021

Informal settlements have been crucial sites of spatial dispossession and neoliberal urbanization with the displacement of the urban poor from profitable urban areas. This study examines the gendered implications of dispossession and changing dimensions of women’s poverty as a result of slum/squatter redevelopment projects. Based on the research of the Kadifekale Urban Transformation Project in Turkey that resettled residents of a highly concentrated Kurdish migrant squatter settlement into a new mass housing estate, the study highlights the impacts of profit-driven urban development projects on women's access to affordable housing, support networks, care work, and employment opportunities. Kurdish women's experiences of displacement and resettlement illustrate in particular the intersectional aspects of gendered dispossession and asset erosion with their exclusion from affordable housing options, dispersal of their communities, and separation from their ethnic employment niches. Drawing upon dispossession and feminist development literature, the study sheds light upon the gendered experiences of displacement, changing livelihood opportunities, gendered access and control over resources, and strategies of resistance that result from slum redevelopment projects.
Enhancing the Accuracy of Peak Hourly Demand in Bike-Sharing Systems using a Graph Convolutional Network with Public Transit Usage Data
Authors: Cho Jung-Hoon , Ham Seung Woo , Kim Dong-Kyu
Published: May 2021

With the growth of the bike-sharing system, the problem of demand forecasting has become important to the bike-sharing system. This study aims to develop a novel prediction model that enhances the accuracy of the peak hourly demand. A spatiotemporal graph convolutional network (STGCN) is constructed to consider both the spatial and temporal features. One of the model’s essential steps is determining the main component of the adjacency matrix and the node feature matrix. To achieve this, 131 days of data from the bike-sharing system in Seoul are used and experiments conducted on the models with various adjacency matrices and node feature matrices, including public transit usage. The results indicate that the STGCN models reflecting the previous demand pattern to the adjacency matrix show outstanding performance in predicting demand compared with the other models. The results also show that the model that includes bus boarding and alighting records is more accurate than the model that contains subway records, inferring that buses have a greater connection to bike-sharing than the subway. The proposed STGCN with public transit data contributes to the alleviation of unmet demand by enhancing the accuracy in predicting peak demand.
Translation and Validation of the Brazilian Portuguese Version of the Broad Conceptualization of Beauty Scale With Brazilian Women
Authors: Junqueira Alessandra Costa Pereira , Tylka Tracy L. , Almeida Sebastião de Sousa , Costa Telma Maria Braga , Laus Maria Fernanda
Published: May 2021

In many countries, women are socialized to adopt a narrow definition of beauty. Research has revealed that, in the United States and China, the ability to broadly conceptualize beauty (perceive beauty in diverse body sizes, shapes, and appearances) is linked to women’s lower anti-fat attitudes, higher body appreciation, and higher well-being. In this study, we translated an existing measure of this construct, the Broad Conceptualization of Beauty Scale (BCBS), into Brazilian Portuguese and evaluated the factor structure and reliability and validity of its scores with a diverse sample of 563 Portuguese women. Findings revealed that the Brazilian Portuguese BCBS contains two factors—external/appearance features of beauty (BCBS-E) and internal features of beauty (BCBS-I)—contrary to the unidimensional factor structure found in previous studies. Support for internal consistency and 3-week test–retest reliability was garnered. Total BCBS and BCBS-E scores evidenced convergent, discriminant, and incremental validity, whereas the BCBS-I did not accrue substantial convergent or incremental validity support beyond its inverse bivariate association with anti-fat attitudes. We recommend the use of the Brazilian Portuguese BCBS in body image research programs as well as clinical practice and prevention programs with Brazilian women seeking support for body dissatisfaction and disordered eating.
The Potential Contribution of the Health System to Reducing Stunting in SUN Countries
Authors: Sawadogo-Lewis Talata , King Shannon E. , Aung Tricia , Roberton Timothy
Published: May 2021

Background:

The global nutrition community has called for a multisectoral approach to improve nutritional outcomes. While most essential nutrition interventions are delivered through the health system, nutrition-sensitive interventions from other sectors are critical.

Objective:

We modeled the potential impact that Scaling Up Nutrition (SUN) interventions delivered by the health system would have on reaching World Health Assembly (WHA) stunting targets. We also included results for targets 2, 3, and 5.

Methods:

Using all available countries enrolled in the SUN movement, we identified nutrition interventions that are delivered by the health system available in the Lives Saved Tool. We then scaled these interventions linearly from 2012 up to nearly universal coverage (90%) in 2025 and estimated the potential impact that this increase would have with regard to the WHA targets.

Results:

Our results show that only 16 countries out of 56 would reach the 40% reduction in the number of stunted children by 2025, with a combined total reduction of 32% across all countries. Similarly, only 2 countries would achieve the 50% reduction in anemia for women of reproductive age, 41 countries would reach at least 50% exclusive breastfeeding in children under 6 months of age, and 0 countries would reach the 30% reduction in low birth weight.

Conclusions:

While the health system has an important role to play in the delivery of health interventions, focusing investments and efforts on the health system alone will not allow countries to reach the WHA targets by 2025. Concerted efforts across multiple sectors are necessary.
Qualitative Assessment of Advanced MRI in Post-Treatment High Grade Gliomas Follow Up: Do We Agree?
Authors: Zakhari Nader , Taccone Michael , Torres Carlos , Chakraborty Santanu , Sinclair John , Woulfe John , Jansen Gerard , Cron Greg , Nguyen Thanh B.
Published: May 2021

Purpose:

MRI is commonly used in follow up of high grade glioma. Our purpose is to assess the interrater agreement on the increasingly used visual qualitative assessment of various conventional and advanced MR techniques in the setting of treated high grade glioma in comparison to the well established quantitative measurements.

Methods:

We prospectively enrolled HGG patients who underwent reresection of a new enhancing lesion on post-treatment 3T MR examination including DWI, DCE and DSC sequences. Two neuroradiologists objectively assessed the diffusion and perfusion maps by placing ROI on representative post-processed maps. They subjectively assessed the post-contrast, perfusion and diffusion sequences. Interrater agreement and concordance correlation coefficient were calculated.

Results:

Twenty-eight lesions were included. The interrater agreement on the qualitative assessment was good for k-trans (k = 0.73), moderate for Vp (k = 0.52), fair for AUC and Ve maps (k = 0.37 and 0.21), fair for corrected CBV (k = 0.39) and poor for the enhancement pattern and presence of diffusion restriction (k = 0.02 and 0.07). The concordance between the quantitative measurements was substantial for AUC and Vp (ρc = 0.98 and 0.97), moderate for k-trans and corrected CBV (ρc = 0.94) and poor for Ve and ADC (ρc = 0.86 and 0.24).

Conclusion:

While the quantitative measurements of DSC and DCE perfusion maps show satisfactory inter-rater agreement, the qualitative assessment has lower interobserver agreement and should not be relied upon solely in the interpretation. Similarly, the suboptimal inter-rater agreement on the interpretation of enhancement pattern and diffusion restriction potentially limits their usefulness in differentiating glioma recurrence from treatment related changes.
Personality states mediate the effect of a mindfulness intervention on employees’ work outcomes: A randomized controlled trial
Authors: Nübold Annika , Hülsheger Ute R
Published: May 2021

In the last decade, organizational researchers have increasingly recognized the value of studying personality states at work. This line of research has to date mainly focused on outcomes of and situational antecedents of personality state change at work. In this study, we draw on social cognitive theory of self-regulation and the social investment principle to test if a structured intervention can bring about changes in employees’ personality states at work. Specifically, we investigate the effect of a four-week low-dose mindfulness intervention delivered via a mobile application on employees’ personality state change in a multi-group experiment with a passive and an active control group. Employees ( N = 162), either practicing mindfulness, doing brain training exercises, or not receiving any treatment were tracked in a diary study across a period of four weeks. Results of growth curve analyses showed that compared to the control groups, the mindfulness intervention led to significantly more increases in employees’ daily mindfulness, emotional stability and agreeableness across the four-week period. Furthermore, daily agreeableness and emotional stability mediated the effect of the intervention on daily job satisfaction and performance. No intervention effects were found for daily openness, conscientiousness, and extraversion. Implications are discussed for research and practice.
Stability and change in vocational interest profiles and interest congruence over the course of vocational education and training
Authors: Etzel Julian M , Nagy Gabriel
Published: May 2021

The current study is concerned with the stability of and changes in vocational interest profiles and interest congruence in vocational education and training (VET). Specifically, we examined (1) the stability of vocational interest profiles, (2) the existence of occupational socialization effects that manifest themselves as increases in person-environment (P-E) congruence, and (3) the question of whether or not changes in P-E congruence are psychologically relevant because they are related to trainees’ attitudes towards their VET course. We used data from a three-wave longitudinal sample comprising N = 2611 trainees from five different VET courses in Germany. Through the use of meta-analytical aggregation techniques, we were able to analyze interindividual differences in intraindividual interest stability and P-E congruence and to relate these differences to trainees’ satisfaction with VET. On average, interest profiles turned out to be highly stable over the entire course of VET. However, we found substantial interindividual and intergroup differences in interest stability. Average P-E congruence increased slightly in two groups, providing only little evidence for the presumed socialization effects. Nevertheless, interindividual differences in P-E congruence and changes in P-E congruence were psychologically relevant because they were linked to trainees’ satisfaction with their VET course and changes therein.
Hyaluronan reduces colitis-induced intraperitoneal inflammation during peritoneal dialysis
Authors: Tomasz Jasiński , Andrzej Bręborowicz
Published: May 2021

Background:

Peritoneal dialysis induces the inflammatory response within the peritoneal cavity, which contributes to the progressive damage of the peritoneum. Due to close contact of the peritoneal cavity and the intestines, there is the possibility that the visceral disorders can affect the intraperitoneal inflammation during peritoneal dialysis.

Objectives:

Study of the effect of acute colitis on the intraperitoneal inflammation in conditions of peritoneal dialysis and evaluation of the protective effect of hyaluronan in that scenario.

Methods:

In rats with the dextran sulphate-induced colitis, 6-h peritoneal dialysis was performed with dianeal 2.5% +/− hyaluronan 10 mg/dL. In the control group, rats without colitis were studied. Peritoneal permeability and dialysate inflammation were studied at the end of the dialysate exchange.

Results:

In rats with colitis, intraperitoneal inflammatory reaction was increased as compared with the control group and reflected by the following studied parameters: dialysate cell count (+26%, p < 0.01), number of neutrophils (+75%, p < 0.01), generation of free radicals in the leukocytes (+70%, p < 0.05), dialysate level of elastase (+102%, p < 0.01), tumor necrosis factor α (+48%, p < 0.01) and monocyte chemoattractant protein-1 (+42%, p < 0.01). Drained dialysate volume was lower (−21%, p < 0.01) and peritoneal permeability increased in rats with colitis (+55%, p < 0.01). In animals with the hyaluronan supplemented dialysis fluids, the intensity of the intraperitoneal inflammation was reduced.

Conclusions:

Visceral inflammation during colitis induces the inflammatory reaction within the peritoneal cavity that may accelerate damage to the peritoneum. Supplementation of the dialysis fluid with hyaluronan reduces the intensity of that effect.
Who Returns? Understanding Varieties of Longitudinal Participation in MIDUS
Authors: Song Jieun , Radler Barry T. , Lachman Margie E. , Mailick Marsha R. , Si Yajuan , Ryff Carol D.
Published: May 2021

Objectives: This study describes a major effort to reinstate dropouts from the MIDUS longitudinal study and compare baseline characteristics among subgroups of participants to better understand predictors of retention, attrition, and reinstatement. Methods: All living dropouts were contacted, and 651 reinstated participants were interviewed in person (31.4% response rate). Age, gender, education, marital status, parental status, and physical and mental health were compared among the following groups: longitudinal sample, reinstated sample, those fielded for reinstatement who did not return, and those who dropped out at the 2nd or 3rd wave. Results: Multivariate analyses revealed that reinstated participants were younger, male, unmarried, and less educated and had children at baseline compared to longitudinal participants. Reinstatement was unsuccessful among those with poorer mental health at baseline compared to longitudinal participants. Discussion: This study informs reinstatement efforts, adjustment for attrition bias, and use of post-baseline data to examine aging consequents of early life vulnerability.
Cadaveric Evaluation of Load to Failure in Canine Gingiva Apposed With Varied Suture Patterns Using Poliglecaprone 25
Authors: Pegg Jane E. , Rawlinson Jennifer E. , Kelley Jennifer L. , Monnet Eric
Published: May 2021

The purpose of the study was to determine the effect of suture pattern and repair length on the load to failure in an ex vivo canine gingival model. Healthy mandibular gingiva and mucosa were harvested from fresh cadavers euthanized for purposes unrelated to the study. Samples were randomly assigned by length and pattern. Lingual and buccal free gingival margins were apposed using a simple interrupted (SI), cruciate (XT), simple continuous (SC), or unidirectional knotless continuous barbed suture (SF) closure technique with USP 4-0 poliglecaprone 25i, ii applied over 2 lengths (3 cm and 6 cm). A custom template was used to ensure uniform suture bite application. Surgical time was recorded. Using a soft tissue mechanical testing frame, samples were tensioned to failure. Testing was video recorded and reviewed in conjunction with the tension trace data for tension at initial failure (Tfail) and maximum tension sustained (Tmax). Two factor ANOVA by length and pattern was performed followed by individual one way T-tests. Statistically significant findings were XT-SC-SF patterns were quicker to perform than SI. SF was more likely to fail by suture breakage than tissue tearing, and SF withstood less tension at the 3 cm length than SI-XT-SC. No significant difference was detected in Tmax or Tfail between SI and SC or XT. The study demonstrates that SC and XT are comparable to SI in tension resistance and faster to perform suggesting that SC and XT could replace SI for extraction site closure although further in vivo testing is required.
Gender Role Attitudes and Labour Market Behaviours: Do Attitudes Contribute to Gender Differences in Employment in Germany?
Authors: Lietzmann Torsten , Frodermann Corinna
Published: May 2021

This article contributes to the literature on persistent gender inequalities in the labour market by investigating gender role attitudes in Germany and their association with labour market behaviour. Based on the German Panel Study ‘Labour Market and Social Security’ (PASS), longitudinal analyses are applied to examine the influence of gender role attitudes and the household context on various employment states. The results reveal that gender role attitudes are crucial for labour market behaviour and that there are differences among women and men in different household contexts. Whereas single men and women do not differ significantly in their employment probabilities, women in couple households are less active in the labour market than their male counterparts. Furthermore, differences in employment are largest in couples with children. Among women, differences in full-time employment by household context become smaller when these women hold egalitarian attitudes.
Experimental and numerical investigation of heat loss in transition modes of buried hot fuel oil pipeline
Authors: Dehdarinejad Mohsen , Behbahani-Nejad Morteza , Hajidavalloo Ebrahim
Published: May 2021

In this research, heat transfer of fuel oil flow through the buried pipeline in three regimes, turbulent, transition, and laminar conditions are investigated. A large-scale laboratory set-up is designed for this purpose and numerical modeling was also performed to study the effect of different parameters. The simulation is based on the fluid's thermophysical properties and the results are validated using experimental data. Due to the strong dependence of viscosity and density of fuel oil on the temperature, regime changes along the pipeline happens which complicate the calculation of friction factor. Using the experiment results and choosing different numerical methods, the acceptable model of friction factor in the transition zone for the experimental pipe and the real pipeline was achieved. Numerical simulation was performed on a 107 km pipeline using a powerful computer network to achieve the results. The approach which is used to simulate laminarization shows just a 3% discrepancy with experimental data. For the real pipeline, about 30 percent of the length is in transition mode from turbulent to laminar. The diameter of 26” is chosen as the most optimal size to transform 180000 barrels per day (BPD). According to the design thickness, diameter, and length of the pipeline, the maximum safe stop time (MSST) of the pipeline is 41 hours which is the most important data in the pipeline's maintenance period. Based on the present experimental data and simulation results, the optimal depth for the least heat loss from this pipeline is 0.9 to 2.7 meters.
Kinematic design of a translational parallel mechanism based on sub-kinematic chain determined workspace superposition
Authors: Shen Huiping , Zhao Yinan , Wu Guanglei , Li Ju , Chablat Damien
Published: May 2021

This paper presents the kinematic design of a translational parallel mechanism (PM) named Vari-Orthoglide by means of the workspace superposition, according to the sub-kinematic chain (SKC) based PM composition principle. The main topological characteristics of the manipulator with two SKCs under study, such as the position and orientation (POC) characteristics, degree of freedom (DOF) and coupling degree are analyzed, which turns out that the coupling degree equals to 1, implying the partially decoupled motion. With the topological characteristics based kinematic modeling principle, a symbolic model of the kinematics is established to derive its symbolic direct and inverse kinematic solutions. Based upon the direct kinematic solution, the workspaces for the two SKCs can be efficiently found. Moreover, the singularity loci are identified for finding the singularity-free workspace, where a regular workspace is fitted as the task workspace as expected. The presented work shows an approach to design translational parallel mechanisms considering motion decoupling and regular workspace, applicable to other types of parallel mechanisms.
Impact of Angular Magnetic Field and Convective Boundary Condition on Heat Transfer of Newtonian Fluid Flow in a Channel
Authors: Saeidi Mostafa Hossein , Bagheri Ali , Ghamati Mehdi , Javanmard Mohsen , Taheri Mohammad Hasan
Published: May 2021

In this study, the heat transfer of a laminar, steady, fully developed, and Newtonian fluid flow in a channel is investigated. The main goal of the present study is solving the hydromagnetic Newtonian fluid flow and heat transfer inside a channel with the angular magnetic field and convective boundary conditions on the walls. As a novelty, the effect of thermal diffusion and advection term the walls and Joule heating in the energy equation has been considered. The governing equations include the continuity, momentum, and energy are presented, and considering the assumptions are simplified. Afterward, employing the dimensionless parameters, the governing equations are transformed into dimensionless forms. The exact solution is provided for the momentum equation. For solving the full energy equation, the analytical collocation method (CM) is conducted. The results are validated using the 4th order Runge-Kutta method. The results demonstrated that the dimensionless velocity, the bulk temperature inside the channel, and the channel wall's heat transfer rate decline when the Hartmann number and the magnetic field angle increase. Since the Prandtl and Eckert numbers reduce, the dimensionless temperature becomes more uniform, and the heat transfer rate on the channel wall decreases. Since the Biot number augments, the dimensionless temperature inside the channel reduces, but the channel wall's heat transfer rate first increases and then reduces.
An investigation into the balancing of high speed, flexible shafts by external application of compensating balancing sleeves
Authors: Knowles Grahame , Bingham Chris , Bickerton Ron
Published: May 2021

The paper investigates the use of compensating balancing sleeves positioned at the shaft’s end for the balancing of high-speed flexible shafts. The balancing sleeve is a new arrangement that creates a pure balancing moment with virtually zero radial reaction forces. For comparison purposes, experimental results from previous research are used to benchmark performance and to demonstrate the benefits newly proposed topology. The new configuration is commensurate with what is required for the Power Turbine (PT) shaft of a twin shaft industrial gas turbine, with an overhung disc. The study is also aimed at bladed shafts, such as those used in high speed gas turbines/compressors, with a view to improving their volumetric efficiency by reducing the formation of relatively large tip leakage gaps caused by shaft deflection/blade wear of abradable seals. It is shown to be practically possible to separate the two main dynamic balancing functions i.e. the control of bearing reaction loads and shaft deflections, thus allowing for their independent adjustment. This enables the required balancing sleeve moment to be determined and set during low-speed commissioning i.e. before any excessive shaft deflection and resulting seal wear occurs, as is typical when final balancing is undertaken at full operational speed.
Perturbation analysis of the two-to-one internal resonance of planetary gear trains
Authors: Xun Chao , Dai He , Long Xinhua , Bian Jie
Published: May 2021

In this study, the two-to-one internal resonance between the first two rotational modes of planetary gear trains (PGTs) is investigated. A purely rotational model is applied considering mesh stiffness variations, tooth separations, and tooth profile modifications (TPMs). Semi-analytical solutions for the internal resonance case are obtained using the method of multiple scales (MMS). The solution equations indicate that the mesh stiffness variations and tooth separations are the main factors causing internal resonance. A validation of the MMS was performed by numerical integration (NI). The results from an example analysis indicate that there exists an internal resonance phenomenon in the case of ωN+2 ≈ ω2, where ω2 and ωN+2 are the natural frequencies associated with the rotational modes, and N is the number of planet gears. Internal resonance in PGTs causes chaos, and part of the energy is transmitted from the ring gear to the sun gear through shocks. Proper TPMs that eliminate the tooth separations could suppress the internal resonance. The internal resonance, in turn, affects the optimal areas of the TPM magnitudes.
A novel adaptive-rear axles steering controller for an 8 × 8 combat vehicle
Authors: Ahmed Moataz , El-Gindy Moustafa , Lang Haoxiang
Published: May 2021

Multi-axle vehicles are widely used in several applications such as transportation, industrial, and military field, because of its higher reliability in comparison with conventional two axles vehicles. Despite that, there is a paucity of research studies that consider lateral stability enhancement of these vehicles, especially on rough terrain. This simulation-based research study fills this gap and introduces a new adaptive Active Rear Steering (ARS) controller that improves the lateral stability of an 8x8 combat vehicle for rough-terrain operation. The developed controller is designed utilizing the Integral Sliding Mode Control theory (ISMC) based on Gain-Scheduled Linear Quadratic Regulator (GSLQR). Besides, the GSLQR control gains are optimized by a Genetic Algorithm (GA) toolbox using a new synthesized cost function to ensure asymptotic stability. Furthermore, a new Adaptive-ISMC (AISMC) is introduced by using genetic programming to generate control equations that can replace the developed high-dimension GSLQR gains and facilitate future hardware implementation. The developed controller is evaluated by performing a series of simulation-based Double Lane Change (DLC) maneuvers on several rough terrains. The evaluation is conducted for both high friction and slippery surfaces at high and moderate speed, consequently. The results show high fidelity and robustness of the developed controller in comparison with a previously designed optimal LQR controller.
A powerful numerical approach for the axisymmetric bending response of shear deformable two-directional functionally graded (2D-FG) plates with variable thickness
Authors: Noori Ahmad Reshad , Temel Beytullah
Published: May 2021

In the present article, a powerful numerical approach is applied to the axisymmetric bending of 2 D-FG circular and annular plates with variable thickness. The mechanical properties of the materials of the plate are assumed to vary continuously both in the radial and thickness directions. The principle of minimum total potential energy is used to obtain the governing equations. Shear deformation is considered based on the first-order shear deformation theory (FSDT). These ODEs are solved via the Complementary Functions Method (CFM) for the first time. The novelty of this paper is the infusion of the CFM to the axisymmetric bending of a wide range of annular or circular plates, with variable thickness, radially FG (RFG), FG in thickness direction, or 2D-FG. In addition to adopting this effective numerical approach to the present class of problems, various parametric studies are presented to show the influence of material variation parameters and geometric constants on the axisymmetric bending response of the considered structures. Results of the proposed approach are validated with those carried out by FEM and those of the available published literature. An excellent agreement is observed.
Tribo-fatigue characteristics of braided wire rope for traction under low cycle bending fatigue
Authors: Han Xiaoran , Zhang Jianbiao , Wang Hui , Cui Weihua , Wang Dagang
Published: May 2021

Braided wire rope as the traction tool is indispensable for stringing conductors in overhead transmission lines. However, rope body wear and fatigue fracture failure often lead to its premature scrap. In this paper, the bending fatigue test of YS 9-8 × 19 braided wire rope for traction was carried out by the test rig. The bending fatigue life of the braided wire rope was discussed by the number of broken wires. Furthermore, the fracture mechanism and wear morphology of the rope wires were analyzed by Ultra-depth three-dimensional microscope combined with the scanning electron microscope. The fatigue damage mechanism was discussed, and the tribo-fatigue characteristics of the wire rope were investigated. Results show that the failure of braided wire rope is the result of the interaction of cyclic bending stress and surface damage. Moreover, most broken wires occur at the place where the rope wires are severely worn. When the bending fatigue cycle is between 2.0 × 104–2.4 × 104, the number of broken wires reaches the scrap standard. Additionally, the bending tribo-fatigue damage of the wires between adjacent strands is the most serious. The primary wear mechanisms of the wires in contact with the pulley are fatigue wear and abrasive wear. In contrast, the wires between adjacent strands are affected by fatigue wear, adhesive wear, and tribo-oxidation.
Design of a novel flat-cloth airway in powder tank based on Taguchi optimization
Authors: Wang Fei , Yan Hao , Zeng Yishan , Xu Wei , Zang Haozhou , Meng Jian
Published: May 2021

The fluidized bed is a key structure in the field of material transportation and is widely used in special automobile and construction powder transportation. A novel flat-cloth airway structure for powder unloading was proposed based on the traditional fluidized bed in this study. To analyze the uniformity of the velocity distribution ( Vu) in the fluidized bed and clarify the interaction mechanism between the geometric structure of the fluidized bed and airflow, 16 geometric structures of the fluidized bed for powder unloading were designed. Different schemes of the fluidized bed were numerically calculated by computational fluid dynamics, and the advantages of each scheme were analyzed by the Taguchi method and multiple regression. The length of the annular vortexes at the inlet of the airways becomes shorter than before as the number of airways increases. Airway height ( H), airway angle ( θ) and airway arc length ( L) exert statistically significant effects. Specifically, H (Delta = 6.45 rank =1) has the greatest effect on signal-to-noise ratios, L (Delta = 2.60 rank =2) has the second greatest effect and θ (Delta = 1.82 rank =3) has the least effect. The optimal combination of geometrical parameters of the fluidized bed is 15 mm H, 51° θ and 200 mm L.
Swarm intelligence based selection of optimal end-milling parameters under minimum quantity nano-green lubricating environment
Authors: Sen Binayak , Hussain Syed Abou Iltaf , Gupta Munish Kumar , Mia Mozammel , Mandal Uttam Kumar
Published: May 2021

With the development of ideas such as green and sustainable processing, recently evolved lubrication methods are commonly used to resolve the disadvantages of the flood lubrication approach. In the minimum quantity lubrication (MQL) technology, a small lubricant mist is inserted into the tool-workpiece interface to achieve better lubrication. The present study, therefore, explored the viability of alumina-reinforced palm oil as a lubricant in the MQL environment. A diverse volume fraction of aluminium (0-1.4%) was mixed with palm oil, and the optimal concentration of nanoparticles (0.8%) was chosen through spectroscopic analysis. Subsequently, twenty-seven milling operations were carried out on Inconel 690 material under the best lubricating medium. Statistical analysis of the machining values was conducted using the main effect plot (MEP), empiric cumulative distribution (ECD), and analysis of variance (ANOVA). Besides, Response surface methodology (RSM) was used to create a mathematical equation between input and machining responses. Finally, the Particle Swarm Optimization (PSO) approach was applied to achieve an optimal machining environment: cutting speed = 88.348 m/min, feed rate = 0.108 mm/tooth, and depth of cut = 1 mm. The optimal machining conditions were confirmed by functional experimentation, which has shown that the mean error between the experimental and the predictive outputs is minimal (less than 2%).
Effect of initial conditions on mean flow characteristics of a three dimensional turbulent wall jet
Authors: Kumar Sarvesh , Kumar Amitesh
Published: May 2021

The effect of initial conditions in a [Formula: see text] sidewall enclosure on the mean flow characteristics of a three dimensional turbulent square wall jet has been studied experimentally. The initial conditions are varied by varying the length of the nozzle; it is varied as l/ h = 10, 50, and 90, where l and h indicates the nozzle length and the side of the square nozzle, respectively. The effect of nozzle length on initial velocity profiles, velocity distribution in lateral and wall normal directions, spread rate, decay of maximum mean velocity, local Reynolds number and similarity behaviour has been studied. The wall normal spread width is higher for the nozzle length l/h = 10 in the near field [Formula: see text] but this trend completely changed after [Formula: see text]. The spread rate is found independent of the initial condition of the nozzles in the fully developed region. The decay rate of maximum mean velocity is found higher for l/ h = 10 in the region of ([Formula: see text], whereas decay rate becomes independent of the initial conditions in the fully developed region [Formula: see text]. The local Reynolds number variation is also estimated along the downstream directions for present case and found that the local Reynolds number [Formula: see text] reaches approximately 56% of the jet exit Reynolds number [Formula: see text] at [Formula: see text] for nozzle length l/ h = 10, while it is 57% and 59% of Rejet for the nozzles [Formula: see text] and [Formula: see text] respectively at the same location. The nozzle l/ h = 10 attained self similar behaviour more quickly as compared to the other nozzles. The sidewall played a significant role which pushed the fluid more towards the center resulting in a lower jet half width in the wall normal direction as compared to the corresponding case, without a sidewall. The decay rates of the maximum mean velocity for all the nozzles are estimated to be 1.08 which is in the accepted range found in the literature.
Tuning of a shunted electromagnetic vibration absorber based on the maximisation of the electrical power dissipated
Authors: Turco Emanuele , Gardonio Paolo , Bo Loris Dal
Published: May 2021

This paper investigates a local tuning approach for a shunted electromagnetic vibration absorber, which is based on the maximisation of the electrical power dissipated by the coil and shunt components. The study considers a simplified problem with a single-degree-of-freedom mechanical hosting system, which is excited by a white noise stochastic force. The hosting system is equipped with a coil-magnet seismic transducer, which is connected to a resistive-inductive shunt. The study examines the effectiveness of the shunted electromagnetic vibration absorber with respect to the following cost functions. Firstly, the reference cost function, which is based on the minimisation of the time-averaged kinetic energy of the hosting system. Secondly, the local cost functions, which are based on: the maximisation of the time-averaged vibration power absorbed by the shunted electromagnetic vibration absorber; the maximisation of the time-averaged mechanical power dissipated by the electromagnetic transducer and the maximisation of the time-averaged electrical power dissipated by the coil and the shunt. The study shows that, provided the transducer is lightly damped, the local cost function based on the maximisation of the electrical power dissipated by the coil and the shunt gives the same optimal tuning parameters than the reference cost function. Therefore, provided the electromagnetic transducer is properly designed, the shunt can be suitably tuned by maximising the time-averaged electrical power dissipated by the coil and shunt. This is a rather appealing practical solution since it can be implemented locally without the need of measuring the response of the hosting system and also it can be implemented in the shunt circuit without the need of extra sensors.
Adjustable impact-time-control guidance law against non-maneuvering target under limited field of view
Authors: Lee Jun-Yong , Kim Hyeong-Geun , Kim H Jin
Published: May 2021

This article proposes an impact-time-control guidance law that can keep a non-maneuvering moving target in the seeker’s field of view (FOV). For a moving target, the missile calculates a predicted intercept point (PIP), designates the PIP as a new virtual stationary target, and flies to the PIP at the desired impact time. The main contribution of the article is that the guidance law is designed to always lock onto the moving target by adjusting the guidance gain. The guidance law for the purpose is based on the backstepping control technique and designed to regulate the defined impact time error. In this procedure, the desired look angle, which is a virtual control, is designed not to violate the FOV limit, and the actual look angle of the missile is kept within the FOV by tracking the desired look angle. To validate the performance of the guidance law, numerical simulation is conducted with different impact times. The result shows that the proposed guidance law intercepts the moving target at the desired impact time maintaining the target lock-on condition.
Structural dynamic response analysis due to the slit flow between the tailplane and the elevator
Authors: Qiu Ju , Tang Jiali , Sun Chundu , Dai Fengyu
Published: May 2021

Any aircraft in flight is subjected to dynamic loads. Following vibration-related accidents, a flow field and vibration analysis can be carried out to analyze the data and study the cause of the accident. When slit airflow enters the cavity between the tailplane structure and the elevator, a mixed vortex is formed. If the vortex-induced vibrational frequency of around 50 Hz happens to be close to the natural frequency of the structure at 46 Hz, it is likely to induce structural vibration (resonance). The resonance can cause excessive fatigue damage which can ultimately lead to structural failure and the loss of the component or the aircraft. Damping methods can be employed to control vibration within the structure by reducing the amplitude of that vibrational motion by 83%. This article details a recreation of one example of structural vibration within an airborne aircraft.
Educational level and risk of sexually transmitted infections among clients of Dutch sexual health centres
Authors: Slurink Isabel AL , Götz Hannelore M , van Aar Fleur , van Benthem Birgit HB
Published: May 2021

This study aimed to assess whether educational level is an independent determinant for sexually transmitted infections (STIs) among clients consulting Dutch sexual health centres (SHCs). With data from the National STI surveillance database (2015–2017), generalized estimating equations corrected for (sexual) risk factors were used to estimate associations between educational level and chlamydia and gonorrhoea among women ( n = 146,020), heterosexual men ( n = 82,882) and men who have sex with men (MSM) ( n = 52,149) and syphilis and HIV among MSM. Compared to the highest educational level (bachelor/master), all lower educational levels were associated with gonorrhoea among women (adjusted odds ratio 1.40; 95% CI 1.18–1.66 for higher general/pre-university level to 3.57; 95% CI 2.66–4.81 for no education/elementary school level) and heterosexual men (respectively 1.36; 1.06–1.74 to 3.84; 2.89–5.09). Women with no education/elementary school level (1.37; 1.17–1.62) and heterosexual clients with (pre-)vocational secondary educational level were more likely to test positive for chlamydia (women: 1.43; 1.39–1.48 and heterosexual men: 1.31; 1.26–1.37) than clients with higher general/pre-university level or bachelor/master level. In MSM, (pre-)vocational secondary educational level was associated with chlamydia (1.16; 1.11–1.22), gonorrhoea (1.15; 1.10–1.21) and syphilis (1.18; 1.08–1.29), and both (pre-)vocational secondary educational level (1.48; 1.25–1.76) and no education/elementary school level (1.81; 1.09–3.00) were associated with HIV. Lower educational levels were independent determinants of STI in SHC clients. Sexual health centres could facilitate STI testing and care among lower educated people by prioritizing their access.
The preparation of modified polyamide clay nanocomposite/recycled maleic anhydride polyamide 6 and blending with low density polyethylene for film blowing application
Authors: Yao Wei-Hua
Published: May 2021

Generally, polyamide cannot be used as film blowing material because of its unsuitable properties. In this study, polyamide 6 clay nanocomposite (cPA) and styrene maleic anhydride copolymer (SMA) were mixed in various ratios for the preparation of modified polyamide 6 clay nanocomposite SxcPAy resins by reactive extrusion. The S1cPA14 resin was blended with recycled maleic anhydride polyamide (rPA) to form the (S1cPA14)x rPAy resins. Finally, they were mixed with LDPE in 1:9 ratio to afford (SxcPAy)1LDPE9 and ((S1cPA14)x rPAy)1LDPE9 resins, respectively, followed by film blowing and the analyses of the physicochemical properties of resins. The FTIR spectrum illustrated that the C=O symmetric and asymmetric absorption fingerprint peaks in the anhydride (-OC-O-CO-) group of SMA disappeared and the new characteristic absorption peak of-CO-N-CO- of imides was observed. The anhydride functional group of SMA underwent reactive extrusion with the terminal amino group of cPA to generate the imides structure. The thermal properties showed that the glass transition temperature and crystallinity of SxcPAy and (S1cPA14)x rPAy resins increased with increasing SMA and S1cPA14 contents. The Tg (85.4.0°C) of (S1cPA14)12 rPA1 resin were enhanced significantly, with 30°C higher than cPA. In terms of tensile mechanical properties, S1cPA14 test pieces demonstrated the highest Young’s modulus and tensile strength. After mixing with LDPE, the tensile mechanical properties of (SxcPAy)1LDPE9 and ((S1cPA14)x rPAy)1LDPE9 resins and films were both higher than that of LDPE. ((S1cPA14)12 rPA1)1LDPE9 film shown the best tensile properties and barrier performance compared with other films due to the optimal rPA content could assisted SMA as a better compatibilizer to improve the dispersion and compatibility of cPA in HDPE. It was worth noting that (SxcPAy)1LDPE9 and ((S1cPA14)x rPAy)1LDPE9 resins were formed by film blowing at the processing temperature of 140°C followed by successful preparation of the film.
Non-wettable antibacterial thin film: PS/Aloe vera and PS/Acalypha indica
Authors: Seifunnisha O , Swathi R , Shanthi J
Published: May 2021

The water and liquid repelling materials due to their low surface energy and specific nanometer and micrometer scale roughness have particular interest due to the great variety of potential applications ranging from self-cleaning surfaces to microfluidic devices. Natural plant-based polymer hydrophobic coatings have several engineering and biomedical applications. In this study, natural plants such as Aloe vera and Acalypha indica were used for preparation of polystyrene hydrophobic film by the dip-coating method. The effects of Aloe vera and Acalypha indica extract on the morphological, structural, optical and antibacterial properties of as-prepared polystyrene thin films were studied. FTIR spectra were carried out to ascertain the presence of functional groups in the prepared polymeric film. Contact angle measurement showed that the PS/ Aloe vera has higher anti-wetting property (CA = 112°) compared to PS/ Acalypha indica (CA = 104°), which could be confirmed by the surface morphology analysis. Furthermore, the effective antibacterial activity against Klebsiella pneumoniae and Staphylococcus aureus was compared by agar-well diffusion method. The observed result reports, PS with Aloe vera film exhibit higher hydrophobic with antibacterial activity compared to PS with Acalypha indica film. In addition, the PS/ Aloe vera coated cotton maintained their repellent properties against various liquids for 10 h, while PS/ Acalypha indica coated cotton exhibit anti-wetting property for 4 h. These findings open up new avenues for the preparation of hydrophobic film for various biomedical applications.
Accounting for natural disasters from a historical perspective: A literature review and research agenda
Authors: Sargiacomo Massimo , Servalli Stefania , Potito Serena , D’Andreamatteo Antonio , Gitto Antonio
Published: May 2021

This study offers an analysis of published historical research on accounting for natural disasters. Drawing on the insights provided by an examination of 35 accounting/business/economic history and generalist journals, 11 articles have been selected and analysed. The analysis conducted on the scattered literature identified the emerging themes, disasters investigated, periods of time explored and main contributions of published research. The analysis is extended by the examination of some key conferences of interdisciplinary history associations, and of the eventual journals/issues where the papers presented were published. The investigation has also been complemented by a brief selection of books showing historical analyses of diverse disasters, typologies and periods of investigation. The stimuli provided by the study have helped to portray the main features of an open research agenda, highlighting possible future research topics and suggesting ancient and recent disasters’ loci to be investigated worldwide.