Near-surface generation of negative ions in low-pressure discharges

Formation processes of negative ions in low-pressure plasmas are not yet fully understood: as a rule experiments reveal higher negative ion density than predicted by the models. In this work we report near-surface generation of negative ions. This hitherto neglected formation mechanism appears to be important in low-pressure discharges and can have large impacts on the bulk plasma chemistry. We monitor energy-resolved positive and negative ion fluxes arriving at the electrodes in an oxygen parallel-plate radio-frequency ~rf, 13.56 MHz! and dc glow plasmas by means of a quadrupole mass spectrometer. Negative ions formed in the plasma volume are observed by extracting them through an orifice in the anode of a dc glow discharge. Unexpectedly, we record large negative ion signals at the cathode of a dc discharge and at the grounded electrode of an rf discharge. These ions are formed in the plasma sheath, in collision processes involving high-energy species. We propose an efficient mechanism of negative ion generation due to ion pair formation in the sheath

Near-surface generation of negative ions in low-pressure discharges

Formation processes of negative ions in low-pressure plasmas are not yet fully understood: as a rule experiments reveal higher negative ion density than predicted by the models. In this work we report near-surface generation of negative ions. This hitherto neglected formation mechanism appears to be important in low-pressure discharges and can have large impacts on the bulk plasma chemistry. We monitor energy-resolved positive and negative ion fluxes arriving at the electrodes in an oxygen parallel-plate radio-frequency ~rf, 13.56 MHz! and dc glow plasmas by means of a quadrupole mass spectrometer. Negative ions formed in the plasma volume are observed by extracting them through an orifice in the anode of a dc glow discharge. Unexpectedly, we record large negative ion signals at the cathode of a dc discharge and at the grounded electrode of an rf discharge. These ions are formed in the plasma sheath, in collision processes involving high-energy species. We propose an efficient mechanism of negative ion generation due to ion pair formation in the sheath

Involvement, topics, and roles of nurses in shared decision-making with patients with dementia in acute hospitals:An integrative review

Aim: To describe nurses' roles, involvement, and topics in shared decision-making with older patients with dementia in acute hospitals. Design: An integrative review. Methods: A systematic search was performed until April 2022 in PubMed, PsychInfo, CINAHL, and Cochrane, followed by a manual search on the reference lists of relevant systematic reviews. Studies were independently screened, appraised using the Joanna Briggs Institute (JBI) methodology, and extracted by two reviewers. Results: Nine studies were included. Nurses were involved as treatment team members, intermediates, or patient supporters. Nurses' roles were most explicit in the preparatory phase of shared decision-making. The step of ‘developing tailor-made options’ was limitedly identified. ‘Deliberating and trying options to reach a decision’ were described from an outsider's perspective in which nurses attempted to influence the decision. In conclusion, nurses primarily have a role in decision-making by supplementing patient information. Patient and Public Contribution No Patient or Public Contribution.</p