Exploring the demands on nurses working in health care facilities during a large-scale natural disaster: often an invisible role within a highly visible event

Nurses are pivotal to an effective societal response to a range of critical events, including disasters. This presents nurses with many significant and complex challenges that require them to function effectively under highly challenging and stressful circumstances and often for prolonged periods of time. The exponential growth in the number of disasters means that knowledge of disaster preparedness and how this knowledge can be implemented to facilitate the development of resilient and adaptive nurses and health care organizations represents an important adjunct to nurse education, policy development, and research considerations. Although this topic has and continues to attract attention in the literature, a lack of systematic understanding of the contingencies makes it difficult to clearly differentiate what is known and what gaps remain in this literature. Providing a sound footing for future research can be facilitated by first systematically reviewing the relevant literature. Focused themes were identified and analyzed using an ecological and interactive systems framework. Ten of the 12 retained studies included evacuation, revealing that evacuation is more likely to occur in an aged care facility than a hospital. The unpredictability of an event also highlighted organizational, functional, and competency issues in regard to the complexity of decision making and overall preparedness. The integrative review also identified that the unique roles, competencies, and demands on nurses working in hospitals and residential health care facilities during a natural disaster appear invisible within the highly visible event

Nanoscale surface domain formation on the +z face of lithium niobate by pulsed UV laser illumination

Single-crystal congruent lithium niobate samples have been illuminated on the +z crystal face by pulsed ultraviolet laser wavelengths below (248 nm) and around (298-329 nm) the absorption edge. Following exposure, etching with hydrofluoric acid reveals highly regular precise domain-like features of widths ~150-300 nm, exhibiting distinct three-fold symmetry. Examination of illuminated unetched areas by scanning force microscopy shows a corresponding contrast in piezoelectric response. These observations indicate the formation of nanoscale ferroelectric surface domains, whose depth has been measured via focused ion beam milling to be ~2 micron. We envisage this direct optical poling technique as a viable route to precision domain-engineered structures for waveguide and other surface applications

Nanoscale piezoelectric response across a single antiparallel ferroelectric domain wall

Surprising asymmetry in the local electromechanical response across a single antiparallel ferroelectric domain wall is reported. Piezoelectric force microscopy is used to investigate both the in-plane and out-of- plane electromechanical signals around domain walls in congruent and near-stoichiometric lithium niobate. The observed asymmetry is shown to have a strong correlation to crystal stoichiometry, suggesting defect-domain wall interactions. A defect-dipole model is proposed. Finite element method is used to simulate the electromechanical processes at the wall and reconstruct the images. For the near-stoichiometric composition, good agreement is found in both form and magnitude. Some discrepancy remains between the experimental and modeling widths of the imaged effects across a wall. This is analyzed from the perspective of possible electrostatic contributions to the imaging process, as well as local changes in the material properties in the vicinity of the wall

Polarity in ZnO nanowires: A critical issue for piezotronic and piezoelectric devices

The polar and piezoelectric nature of the wurtzite structure of ZnO nanowires with a high aspect ratio at nanoscale dimensions is of high interest for piezotronic and piezoelectric devices, but a number of issues related to polarity are still open and deserve a particular attention. In this context, chemical bath deposition offers a unique opportunity to select the O- or Zn-polarity of the resultant nanowires and is further compatible with the fabrication processes of flexible devices. The control and use of the polarity in ZnO nanowires grown by chemical bath deposition opens a new way to greatly enhance the performance of the related piezotronic and piezoelectric devices. However, polarity as an additional tunable parameter should be considered with care because it has a strong influence on many processes and properties. The present review is intended to report the most important consequences related to the polarity in ZnO nanowires for piezotronic and piezoelectric devices. After introducing the basic principles involving crystal polarity in ZnO, a special emphasis is placed on the effects of polarity on the nucleation and growth mechanisms of ZnO nanowires using chemical bath deposition, defect incorporation and doping, electrical contacts and device properties

Zinc oxide nanoparticle-polymeric thin films for dynamic strain sensing

Piezoelectric transducers are becoming increasingly popular for dynamic strain monitoring due to their small form factors and their ability to generate an electrical voltage drop in response to strain. Although numerous types of piezoelectric thin films have been adopted for strain sensing, it has been shown that piezo-ceramics are expensive, brittle, and can fail during operation, while piezo-polymers possess lower piezoelectricity and mechanical stiffness. Thus, the objective of this study is to develop a piezoelectric thin film characterized by high piezoelectricity (i.e., high dynamic strain sensitivities) and favorable mechanical properties (i.e., being conformable to structural surfaces yet stiff). First, zinc oxide (ZnO) nanoparticles are dispersed in polyelectrolyte solutions, and the excess solvent is evaporated for thin film fabrication. The amount of ZnO nanoparticles embedded within the films is varied to yield seven unique sample sets with ZnO weight fractions ranging from 0 to 60%. Upon film fabrication, specimens are mounted in a load frame for monotonic uniaxial testing to explore the films’ stress–strain performance and to subsequently determine their mechanical properties (namely, modulus of elasticity, ultimate strength, and ultimate failure strain). Finally, film specimens are also mounted onto cantilevered beams undergoing free vibration due to an applied initial displacement. The generated voltages in response to induced strains in the beams are recorded, and the piezoelectric performance and dynamic strain sensitivities for the different weight fraction films are calculated and compared. Commercial PVDF thin films are also employed in this study for performance comparison

Resolution considerations in electro-optic single interface deflectors

We discuss the maximum theoretical resolution of a single interface, electro-optically controllable beam deflector in domain-engineered LiNbO3 and report on experimental results for implementation of devices optimized either for maximum resolution or for maximum deflection angle. For the resolution optimized device we observed ~50 resolvable spots for a ±1250-V range, which to our knowledge is a report of one of the highest ratios of resolution per volt from a solid-state electro-optic beam deflector