High-speed machining of thin-walled structures is widely used in the aeronautical industry. Higher spindle speed and machining feed rate, combined with a greater depth of cut, increases the removal ...rate and with it, productivity. The combination of higher spindle speed and depth of cut makes instabilities (chatter) a far more significant concern. Chatter causes reduced surface quality and accelerated tool wear. Since chatter is so prevalent, traditional cutting parameters and processes are frequently rendered ineffective and inaccurate. For the machine tool to reach its full utility, the chatter vibrations must be identified and avoided. In order to avoid chatter and implement optimum cutting parameters, the machine tool including all components and the work piece must be dynamically mapped to identify vibration characteristics. The aim of the presented work is to develop a model for the prediction of stability limits as a function of process parameters. The model consists of experimentally measured vibration properties of the spindle-tool, and finite element calculations of the work piece in (three) different stages of the process. Commercial software packages used for integration into the model prove to accomplish demands for functionality and performance. A reference geometry that is typical for an aircraft detail is used for evaluation of the prediction methodology. In order to validate the model, the stability limits predicted by the use of numerical simulation are compared with the results based on the experimental work.
We present the Latent Timbre Synthesis (LTS), a new audio synthesis method using Deep Learning. The synthesis method allows composers and sound designers to interpolate and extrapolate between the ...timbre of multiple sounds using the latent space of audio frames. We provide the details of two Variational Autoencoder architectures for LTS, and compare their advantages and drawbacks. The implementation includes a fully working application with graphical user interface, called \textit{interpolate\_two}, which enables practitioners to explore the timbre between two audio excerpts of their selection using interpolation and extrapolation in the latent space of audio frames. Our implementation is open-source, and we aim to improve the accessibility of this technology by providing a guide for users with any technical background.
Summary
Serotonin (5‐hydroxytryptamine, 5‐HT), a regulatory amine of mucosal enterochromaffin cells plays an important role in the control of gastrointestinal smooth muscle contraction and epithelial ...secretion. Serotonin has also been associated with gastric ulcers, diarrhoea and abdominal pain. In spite of the high incidence of these gastrointestinal disorders in newborn foals and adult horses, no data are available regarding 5‐HT immunoreactive cells (i.c.) in the gastrointestinal tract (GIT) of foals, and for adult horses, data are incomplete and contradictory. In this study, the distribution and relative frequency of 5‐HT i.c. in the GIT of newborn foals and adult horses were determined immunohistochemically. In foals as in adults, a relatively large number of 5‐HT i.c. were detected in all portions of the GIT. In foals, a significantly higher amount of cells was found in the pyloric region and margo plicatus of the stomach, as well as in the caecum and colon ascendens compared with adults. Our results provided rationale for further research concerning the role of 5‐HT i.c. during the milk diet or in the regulation of gastrointestinal growth/cell proliferation, and in the pathogenesis of gastric ulcers, especially in newborn foals.
The future opportunities for high-density QCD studies with ion and proton beams at the LHC are presented. Four major scientific goals are identified: the characterisation of the macroscopic long ...wavelength Quark-Gluon Plasma (QGP) properties with unprecedented precision, the investigation of the microscopic parton dynamics underlying QGP properties, the development of a unified picture of particle production and QCD dynamics from small (pp) to large (nucleus--nucleus) systems, the exploration of parton densities in nuclei in a broad (\(x\), \(Q^2\)) kinematic range and the search for the possible onset of parton saturation. In order to address these scientific goals, high-luminosity Pb-Pb and p-Pb programmes are considered as priorities for Runs 3 and 4, complemented by high-multiplicity studies in pp collisions and a short run with oxygen ions. High-luminosity runs with intermediate-mass nuclei, for example Ar or Kr, are considered as an appealing case for extending the heavy-ion programme at the LHC beyond Run 4. The potential of the High-Energy LHC to probe QCD matter with newly-available observables, at twice larger center-of-mass energies than the LHC, is investigated.
Twelve bone-setters and 20 clients of bone-setters were interviewed to gather information about the nature and popularity of these traditional health services. The results suggest a high degree of ...confidence in the bone-setter's art, though this is not always well founded.
Weather conditions influence on the formation dynamics of the reproductive organs of pea cultivars with various type of bean has been studied. The genotypic features of flowering, fruit and seed ...formation productivity have been revealed. A high productivity of the seed formation of cultivar «Kaban» with undisclosed beans and equable load distribution of seed weight on productive nodes has been detected. In adverse conditions at «Tan» and «Venets» cultivars the seed weight was formed on two productive nodes. The load of the lower node increased, which share reached 70.8 and 73.8%. «Kaban» cultivar characterized by more synchronous development of productivity on a plant. Almost a half of the seeds weight fell on lower productive node regardless of the year conditions.
We consider an initial value problem for a class of nonlinear fractional differential equations involving Hilfer fractional derivative. We prove existence and uniqueness of global solutions in the ...space of weighted continuous functions. The stability of the solution for a weighted Cauchy-type problem is also analyzed.
The SAGE Working Group on Vaccine Hesitancy developed a vaccine hesitancy measure, the Vaccine Hesitancy Scale (VHS). This scale has the potential to aid in the advancement of research and ...immunization policy but has not yet been psychometrically evaluated.
Using a cross-sectional design, we collected self-reported survey data from a large national sample of Canadian parents from August to September 2016. An online questionnaire was completed in English or French. We used exploratory and confirmatory factor analysis to identify latent constructs underlying parents' responses to 10 VHS items (response scale 1–5, with higher scores indicating greater hesitancy). In addition to the VHS, measures included socio-demographics items, vaccine attitudes, parents’ human papillomavirus (HPV) vaccine decision-making stage, and vaccine refusal.
A total of 3779 Canadian parents completed the survey in English (74.1%) or French (25.9%). Exploratory and confirmatory factor analysis revealed a two-factor structure best explained the data, consisting of ‘lack of confidence’ (M = 1.98, SD = 0.72) and ‘risks’ (M = 3.07, SD = 0.95). Significant Pearson correlations were found between the scales and related vaccine attitudes. ANOVA analyses found significant differences in the VHS sub-scales by parents’ vaccine decision-making stages (p < .001). Independent samples t-tests found that the VHS sub-scales were associated with HPV vaccine refusal and refusing another vaccine (p < .001). Socio-demographic differences in the VHS were found; however, effect sizes were small (η2 < 0.02).
The VHS was found to have two factors that have construct and criterion validity in identifying vaccine hesitant parents. A limitation of the VHS was few items that loaded on the ‘risks’ component and a lack of positively and negatively worded items for both components. Based on these results, we suggest modifying the wording of some items and adding items on risk perceptions.
While brief mindfulness-based interventions have emerged as tools to modulate automatic responding in various domains of health and wellbeing, findings are primarily based on quantitative ...experimental research. However, these group-level findings do not capture the rich subjective experiences of individuals learning mindfulness. In the following qualitative study, we explored how non-meditators learn and apply brief mindfulness instructions in the domain of food cravings. Ten non-meditators listened to ‘normal viewing’ instructions, which asked them to view foods in the way that they normally would. They then viewed a video of attractive foods, and were interviewed about their experiences of learning and applying the instructions. Next, participants listened to a 5-min recording of mindfulness instructions, viewed another food video while applying the mindfulness instructions, and were interviewed again. The data were analysed using thematic analysis. When participants applied brief mindfulness, their relationship to the food stimuli changed such that they started perceiving their experiences as transient. Certain factors (e.g., use of visual metaphors) and processes (e.g., listening to the ‘normal viewing’ instructions first) facilitated this change. The ease of applying the instructions fluctuated with food preferences and perceived strength of cravings. Participants reported that they would apply the instructions in daily life if they felt a need for this, including in domains other than food. However, they anticipated challenges such as remembering and finding time to apply. Our findings highlight the specific aspects that influence how brief mindfulness instructions are learned and applied. These insights may change how brief mindfulness is studied empirically, and may inform the development of simple and empowering techniques that can promote wellbeing in daily life.
Aim
To evaluate ex vivo the incidence of microcracks in root dentine after canal preparation with ProTaper Universal (PTU), RaCe or Safesider instrumentation systems using microcomputed tomography ...(micro‐CT).
Methodology
Thirty freshly extracted mandibular molars with two separate mesial canals and foramina were used. The roots were allocated into three similar groups according to curvature angles and radii of the canals and lengths of the roots. Distal roots were removed and mesial roots were embedded in acrylic resin and instrumented with the PTU, RaCe or Safesider systems up to size 30 (F3 for PTU, size 30, 0.04 taper for RaCe and Safesider) for all instrumentation groups. Dentinal microcracks were evaluated on micro‐CT images of the apical 10 mm of the roots with 1‐mm intervals. Two experienced observers evaluated the images twice in a blinded fashion. The presence of dentinal microcracks (complete/incomplete cracks and craze lines) was noted and analysed statistically using McNemar and chi‐square tests (P = 0.05).
Results
There were microcracks on uninstrumented root sections. All instrumentation systems significantly increased the number of dentinal microcracks when compared to preoperative specimens (P < 0.05). There were new microcracks on the postoperative samples. The PTU system (42%) led to greater number of post‐instrumentation microcracks than Safesider (35%) and RaCe (25%) systems, respectively. The difference between PTU and RaCe system was significant (P < 0.05).
Conclusions
All instrumentation systems significantly increased the number of microcracks compared with preoperative specimens. The PTU system generated more post‐instrumentation dentinal microcracks than the RaCe system.
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