This thesis is devoted to the study of spinning contacts located in bearing between the roller-end and the ring flange. The main direction of the lubricant flow may change when the contact is subjected to skew. This complex kinematics influences the contact behaviour. A dual experimental-numerical approach is proposed to study this problem. The Tribogyr test-rig allows the experimentation of the contact at the 1:1 scale. A film thickness measurement method, based on white light interferometry, was developed on Tribogyr. This method allows the measurement of film thickness between 0 and 800 nm with an accuracy of a few nanometres. The measurement of forces in the main flow direction shows similarities with classical rolling-sliding contacts. However, the friction coefficient is globally lower as soon as spin is involved. Transverse forces are of the same order of magnitude as the longitudinal forces. This is due to transverse shearing caused by the spin. A numerical model has been developed for the simulation of these spinning contacts. The finite element model, which is based on a fully-coupled solving strategy, takes into account the temperature calculation and the lubricant non-Newtonian rheology. Its validation with Tribogyr experimental results in terms of film thickness and friction has been conducted. Spin and skew effects induce high shear-thinning and thermal-thinning of the lubricant that lead to a decrease of the film thickness. Under high spinning condition, the lubricant exiting the contact may be re-injected to the contact inlet. Consequently, the heat transfers between the lubricant and the solids in contact are modified. In contact subjected to high skew, a local increase (dimple) of the film thickness may occur. Important skew may also lead to starvation conditions. Many experimental campaigns, coupled with an intensive use of the numerical model, allowed to understand the physical phenomena involved as well as to predict the efficiency, in terms of power losses, of the spinning contacts.

The content of this thesis is based on the marketing communication in B2B in engineering company SKF CZ, a.s. on the Czech market. First the theory regarding B2B marketing, evaluation of marketing communication, situation analysis and marketing research is introduced. It is followed by situation analysis of the company SKF CZ, a.s. using the 5C method, the description of marketing communication and evaluation of its effectivity based on primary and secondary data. The conclusion consists of appropriate allocation of investments in marketing budget on marketing communication tools and setting appropriate measures for creating the marketing dashboard, which will continuously monitor and evaluate the efficiency of SKF CZ marketing communication.

Reliable energy storage systems are necessary in modern sustainable societies. Storing energy in a spinning flywheel is an old technology which is further investigated in this project. By examining the reactionary forces and friction loss for bearings in a flywheel system, using both MATLAB and Google Spreadsheets, conclusions about the systems design can be drawn. Out of the reactionary forces acting on the rotor, the gravitational force and the mechanical unbalance force proved to be the significant ones, while the gyroscopic reactionary force was relatively small. According to these calculations, to minimize the friction losses, a disc shaped flywheel should be constructed. In general smaller bearing of a chosen bearing type will cause less friction than a bigger bearing of the same type. The bearings also have to be strong and durable enough to meet the requirements of the application.

The influence of central dopaminergic fibers on drug-induced oral activity in rats has not been well studied. Rats were treated 3 days after birth with bilateral intracerebroventricular 6-hydroxydopamine (6-OHDA; 134 ωg total, base form) to destroy dopaminergic fibers in the brain. Control rats received vehicle by the same route. At about 10 weeks of age, a challenge dose of the dopamine D2 receptor antagonist, spiperone (40 ωg/kg, IP), produced an 8-fold increase in the number of oral movements during a 60-minute observation period, vs. the control group. SKF 38393 (3.0 mg/kg, IP), a D1 agonist, produced the same number of oral movements as spiperone in the 6-OHDA group, representing a 2.4-fold increase over the controls. The Bmax and Kd for both D1 and D2 receptors was not changed in rat striatum by neonatal 6-OHDA treatment, even though dopamine content was reduced by 96%. These findings demonstrate that oral activity in rats can be greatly altered, even when there is no change in absolute numbers of D1 and D2 receptors and no change in the ratio of D1:D2 receptors.

Neonatal 6-hydroxydopamine (6-OHDA) treatment of rats is associated with supersensitization of the dopamine (DA) D1 agonist induction of stereotyped and locomotor behaviors. The present study was conducted to determine whether ontogenetic treatments of these rats with the DA D1 receptor agonist, SKF 38393, would produce a maximal DA D1 receptor supersensitivity, as measured by locomotor behavior in adulthood. Rat pups were treated daily with SKF 38393-HCl (3.0 mg/kg per day, i.p.) or saline vehicle for 28 consecutive days from birth. These animals were additionally treated at 3 days after birth with 6-OHDA-HBr (100 μg, in each lateral ventricle, salt form) or its vehicle. Between 6 and 9 weeks locomotor activity or stereotyped behaviors were observed after weekly challenge doses of SKF 38393-HCl (3.0 mg/kg, i.p.). In the neonatal 6-OHDA group, successive SKF 38393 treatments produced progressively greater locomotor activity. In the group of rats treated during postnatal ontogeny with both 6-OHDA and SKF 38393 daily treatments, the first adult challenge dose of SKF 38393 produced an enhanced locomotor response, greater than that seen in other groups (P < 0.01). Subsequent SKF 38393 treatments of this group produced increasingly greater locomotor responses. SKF 38393-induced stereotyped behavioral effects were greater in the 6-OHDA-lesioned groups, whether or not SKF 38393 was administered ontogenetically. Profound reductions (> 99%) of DA and its metabolites were found in the striatum of neonatal 6-OHDA treated rats, regardless of whether SKF 38393 was co-administered ontogenetically. A marked elevation in striatal 5-HT (> 50%) accompanied the DA depletion in the striatum. These findings indicate that neonatal 6-OHDA treatment produces the expected destruction of striatal DA fibers with associated sprouting of 5-HT fibers, while repeated ontogenetic treatments of these rats with a D1 agonist produces partial sensitization of the DA D1 receptors in adulthood.

Our laboratories have been investigating the reactivity of central dopamine D1 and D2/D3 receptors by their corresponding dopamine agonists (SKF-38393 and quinpirole), during development and aging in rats. By evaluating the number of oral movements (a parameter for D1 receptor activation after SKF-38393) and the number of yawns (as a parameter for D3 activation after quinpirole), we demonstrated that not only was there a dose-response activity for both drugs in the two parameters tested, but that the D3 activity was enhanced with the rats' development and aging, due to life-long persisting D3 supersensitivity. In the present study we checked whether D2 and D1 receptors were also sensitized at old age, by measuring behavioral parameters characteristic to D2 (locomotor activity and rearings) and to D1 (grooming time). In the long-term study, male Wistar rats were challenged for 18 months with increasing doses of either SKF-38393, quinpirole or saline. At the age of 19 months they were given a single injection of either drug or saline. In the short-term study, male and female rats were given four single injections of either SKF-38393, quinpirole or saline, with one week intervals, and locomotor time and number of rearings recorded. Long-term quinpirole was found to induce supersensitivity of the D2 receptor complex, demonstrated by both enhanced locomotor time and rearing behavior, while long-term SKF-38393 treatment activated the D1 receptors, as evaluated by grooming time. Short-term quinpirole enhanced supersensitivity of the D2 receptors only in female rats, as assessed by increasing both locomotor time and rearing behavior, reiterating previous results on sex-dependent monoaminergic reactivity.

Male and Female newborn rats were primed with either quinpirole 0.05 mg/kg IP or SKF-38393 0.1 mg/kg IP on days 1-11, 12-22 and 23-33 of their lives. When the rats reached the age of 13 weeks, they were placed on metal rods in an activity avoidance chamber, and light and electric current of 30V/0.8 mA were used on them as conditioning stimuli. Avoidance of the electric shock was considered a positive conditioned reaction. Training and memorizing the conditioned avoidance reflex consisted of a series of ten trials, 60 seconds apart, once a week for ten weeks. The mean number of positive responses after quinpirole was more profound in all priming intervals tested, as compared to SKF-38393, and was higher as the priming started later in life. Significantly higher scores were obtained by the female rats primed with quinpirole, as compared to the male rats primed with the same drug. These differences were much weaker with SKF-38393. These findings confirm that the central D2 receptor system is involved in learn ing and memorizing of Conditioned Avoidance Reflex much more than the D1 receptors do, and that female rats are more sensitive and retentive to this reflex.

Repeated treatments with a dopamine (DA) D2 receptor agonist result in the induction of DA D2 receptor supersensitivity, as evidenced by enhanced behavioral responses to subsequent D2 agonist treatments - a phenomenon known as priming of receptors. Priming of D2 receptors has been well-studied in otherwise intact (non-lesioned) rats. In contrast to D2 priming, repeated treatments with a DA D1 agonist are unable to prime D1 receptors unless nigrostriatal DA fibers are largely destroyed in early postnatal ontogeny. In order to determine if D2 receptors could be primed in rats in which nigrostriatal DA fibers were largely destroyed in early postnatal ontogeny, rats were (a) lesioned at 3 days after birth with 6-hydroxydopamine (67 μg in each lateral ventricle; desipramine, 20 mg/kg IP, 1 h; 6-OHDA), (b) treated daily for the first 28 days after birth with the D2 agonist quinpirole HCl (3.0 mg/kg IP), and (c) observed in adulthood for both quinpirole-induced and SKF 38393- (D1 agonist-) induced locomotor activity and stereotyped activities. In 6-OHDA-lesioned rats in which endogenous striatal DA was reduced by 99%, quinpirole did not produce enhanced locomotor or stereotyped activities. However, SKF 38393 produced increased locomotor and stereotyped activities even after the first dose of SKF 38393. These findings demonstrate that D2 receptors are not primed by ontogenetic quinpirole treatments of neonatally 6-OHDA-lesioned rats, although D2 agonist treatments do at least partially prime D1 receptors in 6-OHDA-lesioned rats.

The main purpose of this thesis work was to halve the cycle time of a grinding process of the groove of carbonitrided ball bearings rings. The study was conducted as a Six Sigma project at SKF in Bari, Italy. Reaching the goal was important for the company as it meant avoiding the purchase of another grinding machine. The groove grinding process on carbonitrided rings features double the cycle time than the same process on through hardened rings and halving it was required to fulfill the volumes demanded. The Six Sigma methodology was applied through the implementation of DMAIC. The analysis of the problems and identification of areas for improvement were carried out deploying different tools such as an Ishikawa diagram, Hypothesis Testing and Statistical Process Control. The outcome of this was the need to optimize the carbonitriding process minimizing the depth of the layer without enlarged carbides in order to render the design of the part easier to machine and subsequently find the process parameters for the groove grinding yielding a cycle time of six seconds. Many trials were conducted with the supplier of carbonitriding, until the carbon and ammonia potentials were set at levels resulting in a depth of the layer allowing the change of the design. An optimizing DOE was instead performed for the grinding process which highlighted the parameters settings yielding the target cycle time. Finally actions and controls to perform in order to maintain the gains were defined.

Cette thèse concerne l’étude des contacts pivotants rencontrés à la conjonction collet-rouleau, entre la bague d’un roulement et le flanc d’un rouleau. L’orientation principale de l’écoulement du lubrifiant peut changer lorsque le contact est mis à l’oblique. Cette cinématique complexe influe sur le comportement du contact. Elle est donc étudiée par une approche duale, expérimentale et numérique. Le banc d’essai Tribogyr permet l’expérimentation du contact à l’échelle 1:1. Une méthode pour la mesure de l’épaisseur du film lubrifiant par interférométrie optique en lumière blanche a été développée sur le banc d’essai et rend possible la mesure d’épaisseurs entre 0 et 800 nm, avec une résolution de quelques nanomètres. La mesure des efforts dans le sens de l’écoulement montre des similitudes avec les contacts de type roulement-glissement bien que le coefficient de frottement soit globalement plus faible. Les efforts transverses ont des valeurs du même ordre de grandeur que les efforts longitudinaux. Ils sont dus au cisaillement transverse induit par le pivotement. Un modèle numérique a été développé dans le but de simuler ces contacts pivotants. Le modèle inclut le calcul des températures et la rhéologie non Newtonienne du lubrifiant dans une stratégie de résolution par éléments finis, totalement couplée. La validation avec des résultats expérimentaux issus de Tribogyr, en épaisseur de film et en frottement, a été effectuée. Il est montré que l’épaisseur de film chute lorsque le pivotement et l’obliquité cisaillent le fluide, entraînant des effets rhéo-fluidifiants et thermo-fluidifiants. En cas de fort pivotement, le lubrifiant sortant peut être réinjecté à nouveau vers l’intérieur du contact et les transferts de chaleur entre lubrifiant et solides en sont fortement perturbés. Une forte obliquité entraîne à la fois la formation d’une augmentation locale de l’épaisseur de film et peut aussi provoquer la sous-alimentation du contact. Plusieurs campagnes expérimentales couplées à l’utilisation intensive du modèle numérique ont permis de comprendre les phénomènes physiques entrant en jeu et de prévoir l’efficacité, en terme de pertes de puissance, d’un contact pivotant. / This thesis is devoted to the study of spinning contacts located in bearing between the roller-end and the ring flange. The main direction of the lubricant flow may change when the contact is subjected to skew. This complex kinematics influences the contact behaviour. A dual experimental-numerical approach is proposed to study this problem. The Tribogyr test-rig allows the experimentation of the contact at the 1:1 scale. A film thickness measurement method, based on white light interferometry, was developed on Tribogyr. This method allows the measurement of film thickness between 0 and 800 nm with an accuracy of a few nanometres. The measurement of forces in the main flow direction shows similarities with classical rolling-sliding contacts. However, the friction coefficient is globally lower as soon as spin is involved. Transverse forces are of the same order of magnitude as the longitudinal forces. This is due to transverse shearing caused by the spin. A numerical model has been developed for the simulation of these spinning contacts. The finite element model, which is based on a fully-coupled solving strategy, takes into account the temperature calculation and the lubricant non-Newtonian rheology. Its validation with Tribogyr experimental results in terms of film thickness and friction has been conducted. Spin and skew effects induce high shear-thinning and thermal-thinning of the lubricant that lead to a decrease of the film thickness. Under high spinning condition, the lubricant exiting the contact may be re-injected to the contact inlet. Consequently, the heat transfers between the lubricant and the solids in contact are modified. In contact subjected to high skew, a local increase (dimple) of the film thickness may occur. Important skew may also lead to starvation conditions. Many experimental campaigns, coupled with an intensive use of the numerical model, allowed to understand the physical phenomena involved as well as to predict the efficiency, in terms of power losses, of the spinning contacts.