Nanobubbles in water and wastewater treatment systems: Small bubbles making big difference.

Since the discovery of nanobubbles (NBs) in 1994, NBs have been attracting growing attention for their fascinating properties and have been studied for application in various environmental fields, including water and wastewater treatment. However, despite the intensive research efforts on NBs' fundamental properties, especially in the past five years, controversies and disagreements in the published literature have hindered their practical implementation. So far, reviews of NB research have mainly focused on NBs' role in specific treatment processes or general applications, highlighting proof-of-concept and success stories primarily at the laboratory scale. As such, there lacks a rigorous review that authenticates NBs' potential beyond the bench scale. This review aims to provide a comprehensive and up-to-date analysis of the recent progress in NB research in the field of water and wastewater treatment at different scales, along with identifying and discussing the challenges and prospects of the technology. Herein, we systematically analyze (1) the fundamental properties of NBs and their relevancy to water treatment processes, (2) recent advances in NB applications for various treatment processes beyond the lab scale, including over 20 pilot and full-scale case studies, (3) a preliminary economic consideration of NB-integrated treatment processes (the case of NB-flotation), and (4) existing controversies in NBs research and the outlook for future research. This review is organized with the aim to provide readers with a step-by-step understanding of the subject matter while highlighting key insights as well as knowledge gaps requiring research to advance the use of NBs in the wastewater treatment industry.

Antibody dynamics post-Comirnaty and CoronaVac vaccination in Malaysia.

Several vaccines have been fast-tracked through clinical trials to mitigate the progression of the SARS­CoV­2 pandemic. We analyzed sequential blood samples from 314 recipients of Comirnaty and CoronaVac in East Malaysia for the spike-binding IgG (IgG-S), nucleocapsid-binding IgG (IgG-N), spike-binding IgM (IgM-S) and serum vitamin D (VitD). A subset of samples was analyzed for the neutralizing antibodies (Ig-RBD). Results showed that IgG-S due to Comirnaty was significantly higher than CoronaVac. IgM-S was detected in 80.0% Comirnaty and 69.5% CoronaVac recipients, while IgG-N was detected in 58.1% CoronaVac but not in Comirnaty recipients. All IgG-S-positive vaccines possessed detectable Ig-RBD after the second dose but with a weak to moderate correlation. The serum VitD levels did not influence the antibody magnitude in both vaccines. In essence, SARS-CoV-2 vaccination is an IgG-S-dominant event, Comirnaty was more effective than CoronaVac in mounting IgG-S and Ig-RBD responses, independent of the patient's VitD level.

The application of computational fluid dynamics and small-scale physical models to assess the effects of operational practices on the risk to public health within large indoor swimming pools.

Swimming pools provide an excellent facility for exercise and leisure but are also prone to contamination from microbial pathogens. The study modelled a 50-m × 20-m swimming pool using both a small-scale physical model and computational fluid dynamics to investigate how water and pathogens move around a pool in order to identify potential risk spots. Our study revealed a number of lessons for pool operators, designers and policy-makers: disinfection reaches the majority of a full-scale pool in approximately 16 minutes operating at the maximum permissible inlet velocity of 0.5 m/s. This suggests that where a pool is designed to have 15 paired inlets it is capable of distributing disinfectant throughout the water body within an acceptable time frame. However, the study also showed that the exchange rate of water is not uniform across the pool tank and that there is potential for areas of the pool tank to retain contaminated water for significant periods of time. 'Dead spots' exist at either end of the pool where pathogens could remain. This is particularly significant if there is a faecal release into the pool by bathers infected with Cryptosporidium parvum, increasing the potential for waterborne disease transmission.

Evaluation of Computational Fluid Dynamics and Coupled Fluid-Solid Modeling for a Direct Transfer Preswirl System.

The prediction of the preswirl cooling air delivery and disk metal temperature are important for the cooling system performance and the rotor disk thermal stresses and life assessment. In this paper, standalone 3D steady and unsteady computation fluid dynamics (CFD), and coupled FE-CFD calculations are presented for prediction of these temperatures. CFD results are compared with previous measurements from a direct transfer preswirl test rig. The predicted cooling air temperatures agree well with the measurement, but the nozzle discharge coefficients are under predicted. Results from the coupled FE-CFD analyses are compared directly with thermocouple temperature measurements and with heat transfer coefficients on the rotor disk previously obtained from a rotor disk heat conduction solution. Considering the modeling limitations, the coupled approach predicted the solid metal temperatures well. Heat transfer coefficients on the rotor disk from CFD show some effect of the temperature variations on the heat transfer coefficients. Reasonable agreement is obtained with values deduced from the previous heat conduction solution.

Postural control at the human wrist.

In our movements and posture, we always act against a physical load. A key property of any load is its elastic stiffness (K), which describes how the force required to hold it must change with position. Here we examine how load stiffness affects the ability to maintain a stable posture at the wrist. Loads having positive (like a spring) and negative stiffness (like an inverted pendulum) were created by varying the position of weights on multiarm rigid pendulum. Subjects (n = 9) held 15 loads (K = +/- 0.04, +/- 0.01 and 0 N m deg(-1) at mean torques of 0.2, 0.4 and 0.6 N m) still for 60 s. Residual wrist movement (sway) increased with mean torque and increased as stiffness became more negative. Large effects of load stiffness were seen at low frequencies (< 1.5 Hz) but not at higher frequencies that reflect load resonance and reflex activity. Subjects accurately perceived their postural sway while holding the loads but measured psychophysical thresholds showed that load stiffness was not perceived. We conclude that load stiffness, independent of force levels, affects the ability to control a load and that the postural control process relies on perception and volitional tracking rather than more automatic reflex pathways. Despite an awareness of their postural errors, we see no evidence for adaptation of postural control processes to compensate for changes in load properties. This is unlike the adaptation of feedforward control processes that produce targeted volitional movements when load properties are altered. We propose that postural control and movement control are fundamentally different neural processes.

Computational fluid dynamics for turbomachinery internal air systems.

Considerable progress in development and application of computational fluid dynamics (CFD) for aeroengine internal flow systems has been made in recent years. CFD is regularly used in industry for assessment of air systems, and the performance of CFD for basic axisymmetric rotor/rotor and stator/rotor disc cavities with radial throughflow is largely understood and documented. Incorporation of three-dimensional geometrical features and calculation of unsteady flows are becoming commonplace. Automation of CFD, coupling with thermal models of the solid components, and extension of CFD models to include both air system and main gas path flows are current areas of development. CFD is also being used as a research tool to investigate a number of flow phenomena that are not yet fully understood. These include buoyancy-affected flows in rotating cavities, rim seal flows and mixed air/oil flows. Large eddy simulation has shown considerable promise for the buoyancy-driven flows and its use for air system flows is expected to expand in the future.

Establishing the scope and methodological approach to out-of-hospital outcomes and effectiveness research.

Outcomes research offers out-of-hospital medicine a valuable methodology for studying the effectiveness of services provided in the out-of hospital setting. A clear understanding of the history and constructs of outcomes research is necessary for its integration into emergency medical services research. This report describes the conceptual framework of outcomes research and key methodological considerations for the successful implementation of out-of-hospital outcomes research. Illustrations of the specific applications of outcomes research and implications to existing methodologies are given, as well as suggestions for improved interdisciplinary research.

Risk adjustment and outcome measures for out-of-hospital respiratory distress.

The purpose of the Emergency Medical Services Outcomes Project (EMSOP) is to develop a foundation and framework for out-of-hospital outcomes research. In prior work, this group delineated the priority conditions, described conceptual models, suggested core and risk adjustment measures potentially useful to emergency medical services research, and summarized out-of-hospital pain measurement. In this fifth article in the EMSOP series, the authors recommend specific risk-adjustment measures and outcome measures for use in out-of-hospital research on patients presenting with respiratory distress. The methodology included systematic literature searches and a structured review by an expert panel. The EMSOP group recommends use of pulse oximetry, peak expiratory flow rate, and the visual analog dyspnea scale as potential risk-adjustment measures and outcome measures for out-of-hospital research in patients with respiratory distress. Furthermore, using mortality as an outcome measure is also recommended. Future research is needed to alleviate the paucity of validated tools for out-of-hospital outcomes research.

Emergency Medical Services Outcomes Project (EMSOP) IV: pain measurement in out-of-hospital outcomes research.

The purpose of the Emergency Medical Services Outcomes Project (EMSOP) is to develop a foundation and framework for out-of-hospital outcomes research. In prior work (EMSOP I), discomfort had the highest weighted score among outcome categories for the top 3 adult conditions (ie, minor trauma, respiratory distress, chest pain) and the first and third highest rankings for children's conditions (ie, minor trauma, respiratory distress). In this fourth article in the EMSOP series, we discuss issues relevant to the measurement of pain in the out-of-hospital setting, recommended pain measures that require evaluation, and implications for outcomes research focusing on pain. For adults, adolescents, and older children, 2 verbal pain-rating scales are recommended for out-of-hospital evaluation: (1) the Adjective Response Scale, which includes the responses "none," "slight," "moderate," "severe," and "agonizing," and (2) the Numeric Response Scale, which includes responses from 0 (no pain) to 100 (worst pain imaginable). The Oucher Scale, combining a visual analog scale with pictures, seems most promising for out-of-hospital use among younger children. Future research in out-of-hospital care should be conducted to determine the utility and feasibility of these measures, as well as the effectiveness of interventions for pain relief.

Emergency Medical Services Outcomes Project III (EMSOP III): the role of risk adjustment in out-of-hospital outcomes research.

The purpose of the Emergency Medical Services Outcomes Project (EMSOP) is to develop a foundation and framework for out-of-hospital outcomes research. Fundamental to that purpose is the identification of priority conditions, risk-adjustment measures (RAMs), and outcome measures. In this third EMSOP article, we examine the topic of risk adjustment, discuss the relevance of risk adjustment for out-of-hospital outcomes research, and recommend RAMs that should be evaluated for potential use in emergency medical services (EMS) research. Risk adjustment allows better judgment about the effectiveness and quality of alternative therapies; it fosters a better comparison of potentially dissimilar groups of patients. By measuring RAMs, researchers account for an important source of variation in their studies. Core RAMs are those measures that might be necessary for out-of-hospital outcomes research involving any EMS condition. Potential core RAMs that should be evaluated for their feasibility, validity, and utility in out-of-hospital research include patient age and sex, race and ethnicity, vital signs, level of responsiveness, Glasgow Coma Scale, standardized time intervals, and EMS provider impression of the presenting condition. Potential core RAMs that could be obtained through linkage to other data sources and that should be evaluated for their feasibility, validity, and utility include principal diagnosis and patient comorbidity. We recommend that these potential core RAMs be systematically evaluated for use in risk adjustment of out-of-hospital patient groups that might be used for outcomes research

EMS Agenda for the Future: Where We Are Where We Want to Be.

During the past 30 years, emergency medical services (EMS) in the United States have experienced explosive growth. The American health care system is now transforming, providing an opportune time to examine what we have learned over the past three decades in order to create a vision for the future of EMS. Over the course of several months, a multidisciplinary steering committee collaborated with hundreds of EMS-interested individuals, organizations, and agencies to develop the "EMS Agenda for the Future." Fourteen EMS attributes were identified as requiring continued development in order to realize the vision established within the Agenda. They are Integration of Health Services, EMS Research, Legislation and Regulation, System Finance, Human Resources, Medical Direction, Education Systems, Public Education, Prevention, Public Access, Communication Systems, Clinical Care, Information Systems, and Evaluation. Discussion of these attributes provides important guidance for achieving a vision for the future of EMS that emphasizes its critical role in American health care. [Delbridge TR, Bailey B, Chew JL Jr, Conn AKT, Krakeel JJ, Manz D, Miller DR, O'Malley PJ, Ryan SD, Spaite DW, Stewart RD, Suter RE, Wilson EM: EMS agenda for the future: Where we are … where we want to be. Ann Emerg Med February 1998;31:251-263.].