1,481 research outputs found
Thermal hydrocracking of indan. Effects of the hydrogen pressure on the kinetics and Arrhenius parameters
The kinetics of the thermal hydrocracking of indan were investigatedin a high-pressure flow reactor at temperatures from 470 to 530°C, total pressures of up to 300 atm, and molar ratios from 3 to 40. The effect of the hydrogen pressure was reflected especially in a change of the experimental rate equations for the formation of toluene from rT=k [indan]0.5 [hydrogen] to rT=k [indan] 0.75[hydrogen]0.75 with hydrogen partial pressureincreasing from 73 to 230 atm. The rate equation of n-propylbenzene remained constant at rPr=k [indan] [hydrogen]1.5. Simultaneously the Arrheniusparameters of toluene changed significantly, while those of n-propylbenzene remained unchanged. \ud
The observed effect of the hydrogen pressure is explained as a change inthe rates of the intermediate reactions; it provides an excellent agreementbetween the theoretical and experimental data. It was found that the steady-state concentration of the hydrogen atoms, which act as chain carriers in the thermal hydrocracking, was much smaller than the thermodynamic equilibrium concentration
In situ IR spectroscopic studies of the cobalt carbonyl/tri-n-butylphosphine hydroformylation catalyst. II
The Temporal Doppler Effect: When The Future Feels Closer Than The Past
People routinely remember events that have passed and imagine those that are yet to come. The past and the future are sometimes psychologically close ( just around the corner ) and other times psychologically distant ( ages away ). Four studies demonstrate a systematic asymmetry whereby future events are psychologically closer than past events of equivalent objective distance. When considering specific times (e.g., 1 year) or events (e.g., Valentine\u27s Day), people consistently reported that the future was closer than the past. We suggest that this asymmetry arises because the subjective experience of movement through time (whereby future events approach and past events recede) is analogous to the physical experience of movement through space. Consistent with this hypothesis, experimentally reversing the metaphorical arrow of time (by having participants move backward through virtual space) completely eliminated the past-future asymmetry. We discuss how reducing psychological distance to the future may function to prepare people for upcoming action
Cost comparison of asthma treatments in 12-week study : caution about matching and short observational follow-up
This review was funded by Observational and Pragmatic Research Institute Pte Ltd.Peer reviewedPublisher PD
Switching Inhalers:A Practical Approach to Keep on UR RADAR
Abstract The choice of an inhaler device is often as important as the medication put in it to achieve optimal outcomes for our patients with asthma and/or COPD. With a multitude of drug–device combinations available, optimization of respiratory treatment could well be established by switching devices rather than changing or even augmenting pharmacological or non-pharmacological therapies. Importantly, while notable between-device differences in release mechanism, particle size, drug deposition and required inspiratory flow exist, a patient uncomfortable with their device is unlikely to use it regularly and certainly will not use it properly. Switching requires a careful process and should not be done without patient consent. Switching devices entails several steps that need to be considered, which can be guided using the UR-RADAR mnemonic. It starts with (i) UncontRolled asthma/COPD (or UnaffoRdable device), followed by RADAR: (ii) review the patient’s condition (e.g. diagnosis, phenotype, co-morbidities) and address reasons for suboptimal control (e.g. triggers, smoking, non-adherence, poor inhaler technique) to be ruled out before switching; (iii) assess patient’s skills related to inhalation (e.g. inspiratory force); (iv) discuss inhaler switch options, patient preferences (e.g. size, daily regimen) and treatment goals; (v) allow patients input and use shared decision-making to decide final treatment choice, acknowledging individual patient skills, preferences and goals; and (vi) re-educate to the new device (at minimum, physical demonstration, verbal explanation and patient repetition, both verbally and physically) and prime the patient for the follow-up (i.e. explain the future patient journey, including multidisciplinary work flows with physicians, nurses and pharmacists)
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