Receiving instrumental support at work: When help is not welcome.

Although the role of social support in promoting employees' health and well-being has been studied extensively, the evidence is inconsistent, sometimes even suggesting that social support might have negative effects. The authors examined some psychological processes that might explain such effects. On the basis of the threat-to-self-esteem model, the authors tested the hypothesis that receiving imposed support elicits negative reactions, which are moderated by someone's need for support. The authors distinguished 3 different reactions: (a) self-related, (b) interaction-related, and (c) physiological. The results of an experiment with 48 temporary administrative workers generally confirmed the hypothesis. Imposed support elicited negative reactions, except when there was an unsolvable problem, but even then the effect of imposed support was not positive but neutral. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Histamine release in sepsis: a prospective, controlled, clinical study

OBJECTIVE: To determine if histamine release occurs in clinical sepsis. DESIGN: Prospective, controlled, clinical study. SETTING: Interdisciplinary intensive care unit and trauma ward. PATIENTS: Sepsis was confirmed in 20 patients (test group) by the criteria of the Veterans Administration Systemic Sepsis Cooperative Study Group (1987) and was verified by positive blood culture. In addition, patients were scored by the Elebute and Stoner Sepsis Score (1983), as modified by Dionigi et al (1985). A concomitant control group consisted of 20 postoperative patients with non-life-threatening trauma to the extremities and without signs of local or systemic infection. INTERVENTIONS: Observational study. Blood samples were collected for determination of plasma histamine concentrations in both groups at the time of study entry and on five succeeding days. MEASUREMENTS AND MAIN RESULTS: The patients were well matched, and the groups were not significantly different for all criteria known to influence histamine release. Comparison of the median values of each group on days 1 through 5 demonstrated significantly higher plasma histamine values in the test group on days 1 through 4, but these values were no longer significantly higher on day 5. While none of the nonseptic control patients achieved a plasma histamine concentration of > 1 ng/mL (the concentration of which was considered to be the pathologic cutoff point representing histamine release), these values (i.e., > 1 ng/ mL) were found in nine of 20 test group patients. In the test group, nonsurvivors (n = 9) had significantly higher plasma histamine concentrations than survivors (n = 11) throughout the whole study and eight of nine nonsurvivors showed a plasma histamine concentration of > 1 ng/mL. Correlation of plasma histamine concentrations on day 1 to sepsis severity (initial Sepsis Score) showed that all but one patient with a combined low Sepsis Score (< 20 points) and histamine concentration of < 1 ng/mL survived, while all patients with a Sepsis Score of > 20 points and histamine release (plasma histamine concentration of > 1 ng/mL) died. CONCLUSION: Increased histamine concentrations were shown to be causally associated (contributory determinant) with sepsis.     

Investigating Gasification Processes of Solid Fuels by in situ Gaspotentiometric Oxygen Probes

This paper describes a novel analytical method that applies a gaspotentiometric oxygen probe (GOP) for characterizing gasification behavior of solid fuels. On the basis of GOP signals a developed gasification model enables the determination of fuel‐specific properties, like effective reaction rate constant and overall activation energy. For its experimental validation two coal cokes were converted with four different gasification agents in a lab‐scale fluidized‐bed reactor. The results obtained will be discussed and compared with literature data. As this advantageous in situ measurement technique is fast, inexpensive, and easy to handle, it makes the GOP a predestined tool for monitoring and controlling gasification processes.     

Verhalten des Stahles X 6 CrNi 18 11 unter kombinierter Kriech- und Wechselbeanspruchung bei 823 K

Experimentelle Untersuchung des Kriech- und Wechseldehnverhaltens des austenitischen Stahles X 6 CrNi 18 11 (Werkstoffnummer 1.4948) bei Beanspruchung durch Kriechen und Ermüden. Auswertung der Ergebnisse unter Anwendung der linearen Schadensregel. Vergleich mit Auslegungskriterien nach dem ASME BPVC.     

Experimental identification of friction and its compensation inprecise, position controlled mechanisms

Methodologies developed for experimentally determining accurate models for the nonlinear friction inherent in most mechanisms are presented. Alternative closed-loop controller strategies for decoupling the effect of friction in order to improve positioning accuracy are also given. The identification methodology is novel in the manner in which it extracts the nonlinear friction properties from the closed-loop errors via an iterative signal processing technique. The discussion is based on both theoretical modeling and on a practical position control problem that was substantially resolved in developing the methodologies. The application was a robotic gripper with a highly preloaded rack-and-pinion mechanism. Both measurement and control design methodologies to help systematically circumvent the problems of nonlinear friction in precise, position-controlled mechanisms are given     

Zur partialladung adsorbierter spezies der ti-amalgam/ti+-reaktion

The following paper reports on the partial charge of adsorbed species of the T1-amalgam/T1⁺-reaction. l- and f-coefficients were determined in a broad potential range and at low reactant concentrations and adsorption densities by impedance measurements. The method of evaluation is presented in detail, including a discussion of the relation of (non-equilibrium) partial charge transfer model to Gibbs adsorption thermodynamics.