scholarly journals The effects of relative food item size on optimal tooth cusp sharpness during brittle food item processing

2014 ◽  
Vol 11 (101) ◽  
pp. 20140965 ◽  
Author(s):  
Michael A. Berthaume ◽  
Elizabeth R. Dumont ◽  
Laurie R. Godfrey ◽  
Ian R. Grosse
Keyword(s):  
Food Item ◽  
Radius Of Curvature ◽  
Fe Model ◽  
Tooth Shape ◽  
Coefficients Of Variation ◽  
Selective Forces ◽  
Item Size ◽  
The Relationship ◽  
Negative Relationships ◽  
Shape Analyses

Teeth are often assumed to be optimal for their function, which allows researchers to derive dietary signatures from tooth shape. Most tooth shape analyses normalize for tooth size, potentially masking the relationship between relative food item size and tooth shape. Here, we model how relative food item size may affect optimal tooth cusp radius of curvature (RoC) during the fracture of brittle food items using a parametric finite-element (FE) model of a four-cusped molar. Morphospaces were created for four different food item sizes by altering cusp RoCs to determine whether optimal tooth shape changed as food item size changed. The morphospaces were also used to investigate whether variation in efficiency metrics (i.e. stresses, energy and optimality) changed as food item size changed. We found that optimal tooth shape changed as food item size changed, but that all optimal morphologies were similar, with one dull cusp that promoted high stresses in the food item and three cusps that acted to stabilize the food item. There were also positive relationships between food item size and the coefficients of variation for stresses in food item and optimality, and negative relationships between food item size and the coefficients of variation for stresses in the enamel and strain energy absorbed by the food item. These results suggest that relative food item size may play a role in selecting for optimal tooth shape, and the magnitude of these selective forces may change depending on food item size and which efficiency metric is being selected.

scholarly journals The impact of job description and career prospect on job satisfaction: A quantitative study in Mauritius

2019 ◽  
Vol 17 ◽  
Author(s):  
Ketan S. Ramhit
Keyword(s):  
Job Satisfaction ◽  
Team Leaders ◽  
Job Description ◽  
Managerial Implications ◽  
Career Prospect ◽  
Value Add ◽  
The Impact ◽  
The Relationship ◽  
Negative Relationships ◽  
Good Career

Orientation: Literature shows that job description and career prospect are connected to job satisfaction and it is seen that, in Mauritius, job description and career prospect impact job satisfaction.Research purpose: The purpose of the study was to determine the relationship between job description, career prospect and job satisfaction in Mauritius.Motivation for the study: It has been noticed that employees are dissatisfied when they perform duties outside their job description and also when they see that they do not have a good career prospect. Despite the existence of several researches, limited research exists in the Mauritian context. The outcome will provide significant relevance to existing knowledge.Research approach/design and method: A quantitative approach was adopted and a survey was conducted in a multinational company in Mauritius. A sample of 132 employees was chosen.Main findings: This research unravelled significant negative relationships between job description, career prospect and job satisfaction. The results revealed that, when duties are not well described or when duties are not in line with current responsibilities, the employees are dissatisfied. Similarly, the greater the chances that employees are not given the opportunity to get promoted, the more they are dissatisfied.Practical/managerial implications: Human resource practitioners, managers and team leaders need to recognise that employee’s moods influence the work pattern in the organisation and a clear job description and an appropriate career plan should exist.Contribution/value-add: Literature on the relationship between job description, career prospect and job satisfaction in the context of Mauritius is almost inexistent. This study will add to existing knowledge.

scholarly journals CAD-Based 3D-FE Modelling of AISI-D3 Turning with Ceramic Tooling

Machines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 4
Author(s):  
Panagiotis Kyratsis ◽  
Anastasios Tzotzis ◽  
Angelos Markopoulos ◽  
Nikolaos Tapoglou
Keyword(s):  
Statistical Model ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Fe Model ◽  
Fe Modelling ◽  
3D Finite Element ◽  
Force Components ◽  
Four Levels ◽  
The Relationship ◽  
Strong Agreement

In this study, the development of a 3D Finite Element (FE) model for the turning of AISI-D3 with ceramic tooling is presented, with respect to four levels of cutting speed, feed, and depth of cut. The Taguchi method was employed in order to create the orthogonal array according to the variables involved in the study, reducing this way the number of the required simulation runs. Moreover, the possibility of developing a prediction model based on well-established statistical tools such as the Response Surface Methodology (RSM) and the Analysis of Variance (ANOVA) was examined, in order to further investigate the relationship between the cutting speed, feed, and depth of cut, as well as their influence on the produced force components. The findings of this study point out an increased correlation between the experimental results and the simulated ones, with a relative error below 10% for most tests. Similarly, the values derived from the developed statistical model indicate a strong agreement with the equivalent numerical values due to the verified adequacy of the statistical model.

Relationship of Semicircular Canal Size to Vestibular-Nerve Afferent Sensitivity in Mammals

2007 ◽  
Vol 98 (6) ◽  
pp. 3197-3205 ◽  
Author(s):  
Aizhen Yang ◽  
Timothy E. Hullar
Keyword(s):  
Semicircular Canal ◽  
High Frequency ◽  
High Gain ◽  
Vestibular Nerve ◽  
Radius Of Curvature ◽  
Horizontal Canal ◽  
Vestibular Nerve Afferents ◽  
The Relationship ◽  
Irregular Afferents ◽  
Anterior Canal

The relationship between semicircular canal radius of curvature and afferent sensitivity has not been experimentally determined. We characterized mouse semicircular canal afferent responses to sinusoidal head rotations to facilitate interspecies and intraspecies comparisons of canal size to sensitivity. The interspecies experiment compared the horizontal canal afferent responses among animals ranging in size from mouse to rhesus monkey. The intraspecies experiment compared afferent responses from the larger anterior canal to those from the smaller horizontal canal of mice. The responses of mouse vestibular-nerve afferents showed a low- and high-frequency phase lead and high-frequency gain enhancement. Regular horizontal-canal afferents showed a sensitivity to 0.5-Hz sinusoidal rotations of 0.10 ± 0.03 (SD) spike · s−1/deg · s−1 and high-gain irregular afferents showed a sensitivity of 0.25 ± 0.11 spike · s−1/deg · s−1. The interspecies comparison showed that the sensitivity of regular afferents was related to the radius of curvature R according to the formula Gr = 0.23R − 0.09 ( r2 = 0.86) and the sensitivity of irregular afferents was related to radius according to the formula Gi = 0.32R + 0.01 ( r2 = 0.67). The intraspecies comparison showed that regularly firing anterior canal afferents were significantly more sensitive than those from the relatively smaller horizontal canal, with Gr = 0.25R. This suggests that canal radius of curvature is closely related to afferent sensitivity both among and within species. If the relationship in humans is similar to that demonstrated here, the sensitivity of their regular vestibular-nerve afferents to 0.5-Hz rotations is likely to be about 0.67 spike · s−1/deg · s−1 and of their high-gain irregular afferents about 1.06 spikes · s−1/deg · s−1.

scholarly journals Morphological Aspects of Ciliary Motility

1967 ◽  
Vol 50 (6) ◽  
pp. 241-258 ◽  
Author(s):  
Peter Satir
Keyword(s):  
The Other ◽  
Radius Of Curvature ◽  
Arc Length ◽  
Apparent Displacement ◽  
Shaft Length ◽  
Ciliary Motility ◽  
Morphological Aspects ◽  
Circular Arcs ◽  
The Relationship

In Elliptio complanatus lateral cilia, two distinct patterns of filament termination can be discerned. In one case, all nine filaments are present and all are single; in the second, at least one filament is missing but doublets are still present. These probably represent different configurations within one cilium in different stroke positions; to get from one to the other, some peripheral filaments must move with respect to others. The data are consistent with the hypothesis that the filaments themselves do not change length, but rather slide past one another to accommodate increasing curvature. The bent regions of the cilium are in the form of circular arcs. In a few cases, apparent displacement of filaments at the tip (Δl) can be shown to be accounted for if we assume that all differences are generated within these arcs. The displacement per degree of bend is 35 A. Regions of bent arc are initially confined to the base of the cilium but move up the shaft as straight regions appear below them. From the relationship between arc length and radius of curvature, a shaft length that is the unit that initially bends and slides may be defined. Quantal displacements of the length of one 14S dynein may perhaps occur at sites between filaments at opposite sides of such a unit as sliding occurs.

Coaches’ impact on youth athletes’ intentions to continue sport participation: The mediational influence of the coach–athlete relationship

2021 ◽  
pp. 174795412199181
Author(s):  
Meredith M Wekesser ◽  
Brandonn S Harris ◽  
Jody Langdon ◽  
Charles H Wilson
Keyword(s):  
Indirect Effects ◽  
Sport Participation ◽  
Self Determination Theory ◽  
Drop Out ◽  
Self Determination ◽  
Need Fulfillment ◽  
Sports Teams ◽  
Youth Athletes ◽  
The Relationship ◽  
Negative Relationships

About 70% of youth athletes drop out of sport by age 13. Self-determination theory has been utilised to investigate athletes’ motivations for behaviours including sport persistence (i.e. continuation) and suggests that the coach can be an influence on such motivations. Basic need fulfillment via interpersonal coaching behaviours, the coach-athlete relationship (CAR), and intentions to continue sport participation have been examined independently and in various combinations and directions, but these variables have not been examined collectively in this manner. The purpose of this study was to determine if CAR quality mediates the relationship between interpersonal coaching behaviours and intentions to continue sport participation. Surveys were administered to 148 athletes ages 11 to 16 from organised sports teams. No significant indirect effects of mediation could be established. However, there was a significant and direct effect of competence-supportive behaviours on intentions ( β = .341, p < .001). Overall, the total effects model was significant ( F(1,146) = 18.762, p < .001, adjusted R2 = .114). Significant positive relationships were shown among supportive coach behaviours and CAR quality in addition to CAR quality and intentions. Negative relationships were demonstrated among thwarting coach behaviours and CAR quality. Results support that coaches’ competence-supportive behaviours can positively impact CAR quality and intentions to continue sport participation in youth athletes.

Effects of countersunk hole geometry errors on the fatigue performance of CFRP bolted joints

2021 ◽  
pp. 095440542110285
Author(s):  
Xuda Qin ◽  
Xingfeng Cao ◽  
Hao Li ◽  
Meng Zhou ◽  
Ende Ge ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Bolted Joints ◽  
Fatigue Performance ◽  
Machining Process ◽  
Fe Model ◽  
Hole Making ◽  
Hole Geometry ◽  
Geometry Error ◽  
The Relationship ◽  
Hole Machining

Due to good aerodynamic performance and reliability, countersunk bolt joint is one of the most commonly used connection methods for carbon fiber reinforced polymer (CFRP) components in the aircraft. However, the countersunk hole machining process is inevitably accompanied by geometric errors, which will directly affect the mechanical properties of the joint structure. This paper presents a numerical and experimental investigation on the effect of countersunk hole geometry errors on the fatigue performance of CFRP bolted joints. FE model of CFRP countersunk bolted joints with designed geometry errors are established, and the rationality of the FE analysis was verified by fatigue life and failure forms. The CFRP bolted structure failure mechanism under fatigue load and influence of hole-making geometry error (including countersunk fillets radius, countersunk depth, and countersunk angle) on the fatigue life are investigated. Based on the relationship between fatigue life and the geometry error, the corresponding tolerances for CFRP bolt joint countersunk hole are determined as well. The research results can provide a reference for establishing reasonable geometric accuracy requirements for CFRP joint hole machining.

scholarly journals Attitudes toward Persons with Disabilities: A Relationship of Age, Gender, and Education of Students

2017 ◽  
Vol 4 (4) ◽  
Author(s):  
Ajay Kumar Maurya ◽  
Ashok Parasar
Keyword(s):  
Sampling Technique ◽  
Older Students ◽  
Point Scale ◽  
Persons With Disabilities ◽  
Gender And Education ◽  
And Gender ◽  
Education Of Students ◽  
Relationship Of ◽  
The Relationship ◽  
Negative Relationships

The study was conducted to see the relationship between students’ attitude towards disability with reference to age, gender and education. The main aim of this study was to assess whether older students has positive attitude than younger; whether boys and girls have different attitude towards disability and whether the there is any impact of education on attitude toward disability? Method: Data was collected from general population through random sampling technique from six different schools. Participants were selected from the four classes (9, 10 11, and 12) with equal number of Boys and girls. To assess the Attitude towards disability, the Harold E. Yuker J. R. BlockJanet H. Youinng 6 point scale with 20 items scale was administered. Results: In this study positive correlation was found between ATDP & Age, ATDP & Education, and Negative correlation between ATDP and Gender was found. Conclusions: Participant’s Age and Education have positive relationship with their attitudes towards disability; negative relationships was found between gender and attitude towards disability.

scholarly journals Estrés, Depresión Y Consumo De Alcohol En Estudiantes De Bachillerato De México: Diferencias Por Sexo Y Escuela

2016 ◽  
Vol 12 (32) ◽  
pp. 94
Author(s):  
Rosa Vargas Almendra ◽  
Arturo del Castillo Arreola ◽  
Rebeca María Elena Guzmán Saldaña
Keyword(s):  
High School ◽  
High School Students ◽  
Pearson Correlation ◽  
Physical And Mental Health ◽  
School Students ◽  
Factorial Anova ◽  
Age Range ◽  
The Relationship ◽  
Negative Relationships ◽  
Type Of School

Stress in teenagers studying high school is a health problem of great importance as not only affects behavior but also affects physical and mental health of this population, increasing the likelihood of depression occur and use alcohol as a means of coping with it. Objective: To determine the interaction by sex and type of school, as well as the relationship between levels of stress, depression and alcohol of high school students in two states in Mexico. Material and Methods: 129 students from two high schools in the states of Hidalgo and Mexico respectively selected through a non-probability sampling. The age range was from 16 to 21, M = 17 years, SD = .893. 51.2% were men and 48.8% women. Perceived Stress Scale (EEP) was used, the Beck Depression Inventory and Identification Questionnaire disorders due to alcohol consumption (AUDIT). They were conducted descriptive analyzes, Pearson correlation analysis and factorial ANOVA 2x2. Results: Significant negative relationships between stress and depression (r = .552, p <0.05) were found, also significant differences by gender in alcohol F (3,70) = 3.283, p ≤ .05 and significant differences by school in depression variable F (3,125) = 3.690, ≤ .05. Conclusion: These results provide insight into the association between different risk facotres student population so that from it culturally relevant psychological interventions that affect the prevention of health problems in this population are designed.

Field Transforms for Multilayered Cylindrical and Spherical Structures of Finite Conductivity

1975 ◽  
Vol 53 (11) ◽  
pp. 1078-1087 ◽  
Author(s):  
E. Bahar
Keyword(s):  
Radius Of Curvature ◽  
Finite Conductivity ◽  
Electromagnetic Propagation ◽  
Wave Guides ◽  
Spherical Structures ◽  
Fourier Type ◽  
The Relationship ◽  
Conducting Cylinders ◽  
Dielectric Structures ◽  
Watson Transform

Problems of propagation around multilayered cylindrical or spherical structures possessing highly conducting cores have been analyzed in terms of discrete sets of modes. However, when propagation through the core of the structure is significant and of particular interest, the discrete set of modes is not suitable for the complete expansion of the electromagnetic fields.To provide a suitable basis for the expansion of the electromagnetic field in nonuniform multilayered, cylindrical or spheroidal, dielectric structures we derive expressions for the electric and magnetic field transforms consisting of both a discrete and a continuous spectrum of waves. The relationship between these transforms, the Kontorowich–Lebedev transform, and the discrete Watson transform is discussed. When the radius of curvature of the structure is infinite these transforms merge with generalized Fourier type transforms.The transforms can be used to investigate electromagnetic propagation through irregularly shaped dielectric wave guides, and through irregularly shaped spheroids. It can also be used to solve the problem of propagation in the interior (concave side) of irregularly shaped conducting cylinders or spheroids.

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