Rolling bearing defect detection and diagnostics

This article presents experimental studies on deep groove ball bearing vibrations and the results of simulation. A special test stand was designed to find failure modes. Acceleration, displacement, loading forces, shaft speed, acoustic pressure and temperature were measured. The measured parameters were not constant during the experiment; thus a number of state indicators were found. The amplitude of displacement is sensitive to rolling bearing degradation. At the same time, acceleration is sensitive to the defects of the races, whereas temperature is not. Moreover, acoustic pressure provides valid information about the defects of the races

The Equivalent Force System Of A Monopole Source In A Fluid-Filled Open Borehole

The elastodynamic body-wave field outside a fluid-filled open borehole due to a monopole source in the fluid, is reduced to the radiation-field due to a suitable equivalent force system (EFS) in the absence of the borehole, consisting of a monopole plus a vertical dipole. Theoretical seismograms of the EFS displacements in the solid are shown to be in excellent agreement with those obtained from the exact solution to the fluid-filled open borehole problem.United States. Defense Advanced Research Projects Agency (Contract F1962889-K-0020

Assessing post-cue exposure craving and its association with amount wagered in an optional betting task

Background and aims: The current study was designed to assess the impact of wins and losses in simulated blackjack on craving to gamble and to assess the extent to which this craving was associated with actual wagering in an optional gambling task. Methods: Participants were undergraduates attending a large Midwestern university in the United States. They completed the Gambling Urge Scale (GUS) and then were randomized to either a condition in which they would win 15 hands of blackjack (Win condition; n = 41) or lose 15 hands (Lose condition; n = 37) out of a total of 20 hands. After playing blackjack and completing several additional questionnaires, participants had the chance to wager their $5 compensation for the opportunity to win$50. Results: GUS scores increased significantly following blackjack, regardless of condition. We also found that post-blackjack craving was significantly associated with the amount participants wagered in the optional betting task, such that greater craving was associated with higher amount wagered. Conclusions: These findings provide further support for the construct validity of the GUS, provide novel findings regarding the effects of wins and losses when gambling, and provide evidence of an association between craving and a behavioral betting task

Simulation of rolling bearing vibration in diagnostics

This article presents results on simulation of deep groove ball bearings vibrations. Contacts between rolling elements and the races can be modelled as the Hertzian contact. This contact is on-linear, thus introduces non-linear spring forces, in consequence this vibrations are non-linear. Positions of rolling elements are functions of time, thus these vibrations can be considered as parametric vibrations. In consequence rolling bearings are active non-linear elements, which excite vibrations. This approach reflects the nature of rolling bearings vibrations. The following phenomena have been observed: bistability, jump of amplitude, opposing period-doubling bifurcations “a bubble”, period-doubling bifurcations leading to chaos, bifurcation directly leading to chaos, chaotic vibrations, windows of periodic vibrations, “noisy periodicity”, and chaotic explosion. Moreover, amplitudes of vibrations have been presented against clearance. This provides an opportunity to select failure modes. Unfortunately, relations clearance-amplitude and amplitude-clearance are ambiguous, which makes machinery diagnostic a difficult issue

Tube Waves, Seismic Waves And Effective Sources

A simple asymptotic analysis, based on the smallness of the ratio of the borehole radius to the wavelength, reveals the interaction between tube waves and seismic waves. The pressure field in a tube wave acts as a secondary source of seismic waves and conversely an incoming seismic wave excites a tube wave. The asymptotic analysis leads to a characterization of these sources in terms of the solution to two-dimensional elastostatic problems. These may be solved exactly when the borehole has an elliptical cross-section even in an anisotropic formation. Also the borehole need not be straight provided that its radius of curvature is large compared with a wavelength

Insulin-like Growth Factor 1 Genotype Influences Muscle Strength Response to Sterngth Training in Older Adults

Strength training (ST) is considered an intervention of choice for the prevention and treatment of sarcopenia. The insulin-like growth factor 1 protein (IGF-I) plays a major role in ST-induced skeletal muscle hypertrophy and strength improvements. A microsatellite repeat in the promoter region of the IGF1 gene has been associated with IGF-I blood levels and phenotypes related to IGF-I in adult men and women. To examine the influence of this polymorphism on muscle hypertrophic and strength responses to strength training (ST), we studied 67 Caucasian men and women before and after a 10-week single leg knee extension ST program. One repetition maximum (1RM) strength, muscle volume (MV) via computed tomography (CT), and muscle quality (MQ) were assessed at baseline and after 10 weeks of training. The IGF1 repeat promoter polymorphism and three single nucleotide polymorphisms (SNP) were genotyped. For the promoter polymorphism, subjects were grouped as homozygous for the 192 allele, heterozygous, or non-carriers of the 192 allele. After 10 weeks of training, 1RM, MV, and MQ increased significantly for all groups combined (P < 0.001). However, carriers of the 192 allele gained significantly more strength with ST than non-carriers of the 192 allele (P = 0.02). There was also a non-significant trend for a greater increase in MV in 192 carriers than non-carriers (P = 0.08). No significant associations were observed for the other polymorphisms studied. Thus, these data suggest that the IGF1 promoter polymorphism may influence the strength response to ST. Larger sample sizes should be used in future studies to verify these result

Zum Einfluss von Eisenchelatoren auf die intestinale Mikrozirkulation bei systemischer Inflammation und experimenteller Sepsis

Eisen als wichtigstes Spurenelement im menschlichen Körper bedingt, dass für nahezu alle Erkrankungen, insbesondere chronische und akute Entzündungsreaktionen eine fein regulierte Eisenhomöostase von besonderer Bedeutung ist. Ziel dieser Arbeit war es den Einfluss von zwei neuen Eisenchelatoren, DIBI und MAHMP auf die intestinale Mikrozirkulation bei experimenteller Sepsis zu evaluieren. Im Rahmen einer Sepsis können Eisenchelatoren eine mögliche neue Therapieoption darstellen, indem sie zum einen in verschiedenen Kompartimenten freies Eisen binden können, welches folglich nicht mehr zur Generierung reaktiver Sauerstoffspezies zur Verfügung steht, und zum anderen die Bioverfügbarkeit freien Eisens für Stoffwechselprozesse und Zellteilung pathogener Keime reduzieren. Hierzu führten wir intravitalmikroskopische Untersuchungen des Darmes an zwei murinen Modellen der experimentellen Sepsis durch. Wir konnten zeigen, dass bei Endotoxinämie eine Behandlung mit MAHMP die Leukozytenaktivierung reduziert, die intestinale Kapillarperfusion verbessert und vor einen histologischen Mukosaschaden schützt und somit anti-inflammatorisch wirkt. Im CASP-Modell führte die Behandlung einer polybakteriellen Peritonitis mit DIBI zur signifikanten Reduktion der Leukozytenaktivierung. Dies begründen wir hauptsächlich durch eine antibakterielle Wirkung von DIBI, welche durch extrazelluläre Eisenrestriktion quantitativ das Bakterienwachstum reduziert, und folglich über eine Reduktion Toxin-vermittelter, intrazellulärer Signaltransduktionskaskaden sekundär antiinflammatorisch wirkt.Introduction: Iron homeostasis is intimately connected to the inflammatory response in severe infections. Free intracellular and extracellular iron is involved in the generation of reactive oxygen species. Furthermore, during infections bacterial growth depends significantly on iron availability. Hence, aim of the study was to evaluate potential anti-inflammatory properties of two new iron chelators, DIBI and MAHMP, within the intestinal microcirculation, which plays an important role in the pathogenesis of septic multiorgan failure. Methods: We used two models of experimental sepsis - lipopolysaccharide(LPS)-induced systemic inflammation (28 mice) and the Colon Ascendens Stent Peritonitis (CASP)-induced sepsis model (6 mice). Capillary perfusion and leukocyte activation within the intestinal microcirculation was studied by intravital microscopy (IVM) in the following groups: control, DIBI, MAHMP, LPS untreated, CASP untreated, LPS+DIBI, LPS+MAHMP, CASP+DIBI Results: DIBI and MAHMP improved the capillary perfusion of the intestinal muscular and mucosa layers in the LPS-model. Leukocyte adherence to the endothelium of submucosal venules was significantly reduced by both substances. This effect was even more pronounced in the bacterial sepsis model (CASP+DIBI). Discussion: The iron chelator DIBI improved capillary perfusion and reduced leukocyte adhesion in the intestinal microcirculation in both LPS- and CASP-induced experimental sepsis. We propose anti-inflammatory and antibacterial effects of iron chelation in experimental sepsis

Gra masek i pożądań – o komedii Nigdy nic nie wiadomo Bernarda Shawa

Bernard Shaw’s Plays Pleasant are an example of realization of convention of realistic social dramaturgy as well as a proof of a serious reflection on condition and construction of the institution of marriage and the family of Victorian era. You Never Can Tell which is an object of analyses in this article raises the question of dramatization of behaviours of individuals, masks worn by individuals because of social situations, a strategy of seduction (social life as drama/game). The institution of marriage functions as an object of critique, a tool in the games between sexes and as an object of affirmation. The “duel of sexes” is the key problem of comedy. Bernard Shaw presents the mechanism of arousing of desire as well as demonstrating that love is a form of game and desire is the basic experience in the construction of human identity