Alexithymia, emotional awareness and perceived dysfunctional parental behaviors in heroin dependents

© Springer Science+Business Media New York 2013The original publication is available at www.springerlink.com © Springer Science+Business MediaThe aim of this study was to analyse alexithymia and deficits in emotional awareness, in heroin addicts, and their relationship with perceptions of early parental interactions. The sample included 99 opiate dependent outpatients and 43 healthy controls. Assessment was performed using the Toronto Alexithymia Scale, the Levels of Emotional Awareness Scale, the Inventory for Assessing Memories of Parental Rearing Behavior, the Mini-Mental State Examination and the Hospital Anxiety and Depression Scale. Findings suggest parental representations, which were mostly characterized by emotional unavailability and a rejection interaction pattern, significantly related to alexithymia. Emotional awareness was associated with the number of years of drug use and methadone level. Negative affect was associated with alexithymia but not to emotional awareness. Regression analyses emphasized the influence of perceived dysfunctional parenting behaviors in alexithymia and difficulties in identifying feelings, particularly an interaction with paternal rejection, moderated by self-reported anxiety. These results are discussed addressing comprehensive issues of emotion regulation and treatment strategies in heroin dependence

Relating grip characteristics to the dynamic response of tennis racquets

Vibration levels are of major concern in tennis racquet design. If the racquet structure is to be dynamically tuned so that negative consequences of racquet vibration are alleviated, the parameters defining the degree to which vibration is transferred to the athlete must first be quantified and fully understood. This paper investigates some of the main parameters contributing to vibration transfer in tennis racquets via the hand grip. The work presented here allows for a correlation to be established between grip characteristics and vibration response of the racquet. In-order gain more insight into the mechanics of vibration transfer to the athlete the tennis grip is quantified here in terms of pressure distribution and its relationship with amplitude of vibration in frequency and time domain. The pressure distribution in the grip is determined using hydrocell pressure sensors. Grip anticipation times have been measured and assessed giving a comprehensive understanding of the tennis grip dynamics. The gripping characteristics during ball impact are related to the dynamic response of the tennis racquet

Integrating the design for environment approach in sports products development

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Life cycle assessment and evaluation of environmental impact of sports equipment

Design of sports equipment is primarily performance driven. As a consequence of this approach the sports equipment industry has eagerly adopted new materials and processes over the years that provide the competitive edge but which have unintentionally placed additional burdens on the environment. With the introduction of more rigorous environmental regulations in the developed countries there has been a further shift of manufacturing operations to areas of the world where such policies are more relaxed. There is much evidence that such practices have caused further global environmental degradation. With around 80% of the environmental burden of a product determined during the design stage it is clear that new design practices and tools are required in order to address this problem in a more sustainable way. Environmental concerns need to become a design objective rather than a constraint. This paper discusses the principles and strategies for environmentally sound design of sports equipment and in particular the eco-design approach based on life cycle assessment (LCA). A case study is presented involving comparative environmental life cycle assessment of carbon fibre and glass fibre composite tennis racquets using software EcoScan

Kinematics of a smart variable caster mechanism for a vehicle steerable wheel

The lateral force of a tyre is a function of the sideslip and camber angles. The camber angle can provide a significant effect on the stability of a vehicle by increasing or adjusting the required lateral force to keep the vehicle on the road. To control the camber angle and hence, the lateral force of each tyre, we can use the caster angle of the wheel. We introduce a possible variable and controllable caster angle in order to adjust the camber angle when the sideslip angle cannot be changed. As long as the left and right wheels are steering together according to a kinematic condition, such as Ackerman, the sideslip angle of the inner wheel cannot be increased independently to alter the reduced lateral force because of weight transfer and reduction of the normal load F z A variable caster mechanism can adjust the caster angle of the wheels to achieve their top capacity and maximise the lateral force, when needed. Such a system would potentially increase the safety, stability, and maneuverability of the vehicles. Using the screw theory, this paper will examine the kinematics of a variable caster and present the required mathematical equation to calculate the camber angle as a function of suspension mechanism parameters and other relevant variables. Having a steered wheel about a tilted steering axis will change the position and orientation of the wheel with respect to the body of the car. This paper provides the required kinematics of such a suspension and extracts the equations in special practical situations. The analysis is for an ideal situation in which we substitute the tyre with its equivalent disc at the tyre plane. © 2012 Copyright Taylor and Francis Group, LLC

Development of a fast-solving numerical model for the structural analysis of cricket balls

In cricket, high speed impacts occur between the cricket ball, the bat, players and their protective equipment. Improved understanding of impact dynamics has the potential to significantly improve the development of cricket equipment and also contribute to improving the player safety and performance. In particular, the development of high performance cricket balls with enhanced structural properties (e.g. improved durability) would benefit greatly from such insight. This article presents the development of two fast-solving numerical models as well as a universal FE model for the structural analysis of cricket balls. The models were developed using experimental data obtained from drop tests and high speed impact tests. These models predict impact characteristics with very little computing cost. A universal Finite Element (FE) ball model has also been developed using ABAQUS, which combines an FE model template and a material parameter selection tool based on an Artificial Neural Network (ANN) model. This approach allows for rapid model development while producing accurate results at different impact speeds. Comparison of results revealed good agreement between simulation and experimental results. The developed FE-ANN model can be used to predict the impact behaviour of different types of cricket balls under various dynamic conditions. This flexibility represents an advantage that can be utilized by sports equipment developers to rapidly develop different cricket ball models needed for inclusion in larger simulations involving impact of a cricket ball with other objects. This represents an invaluable tool for facilitating design, analysis and structural optimisation of cricket-related sport equipment

Development of an FE model of a cricket ball

Studies of impact dynamics of cricket balls have the potential of significantly improving the development of cricket equipment and also contribute to improving the player's safety and performance. This work presents the development of a detailed multi-layer FE model for the structural analysis of cricket balls. The model was derived using experimental data obtained from tests developed for this purpose, including drop tests and high speed impact tests. The multi-layer, multi-material FE model was constructed using ABAQUS. Calibration of the model involves a multidisciplinary optimization technique. Comparison shows good agreement between experimental results and predictions from the refined model