The influence of rotor downwash on spray distribution under a quadrotor unmanned aerial system

This paper investigates how sprays are influenced by rotor downwash produced by a quadrotor Unmanned Aerial System when crop spraying. Computational Fluid Dynamics simulations, using RANS modelling for the flow field and Lagrangian particle tracking for the spray, are conducted for several single-rotor and multi-rotor cases with the spray injected underneath the centre of the rotor. The rotor is modelled using a Blade Element actuator disc model. The accuracy of the computational approach is demonstrated by good agreement with experiment for both thrust and deposited spray pattern for a single rotor in an indoor environment. Both the experimental and computational results show that the peak in the spray distribution under a single rotor increases as rotor thrust increases, whilst increasing the rotor height above the ground causes this peak to decrease. The validated Computational Fluid Dynamics method is then used to simulate flight conditions for single-rotor and multi-rotor cases. These show the existence of a critical flight speed, above which the spray impinging on the ground no longer contains a notable peak. This behaviour is seen to be due to the streamtube detaching from the ground and no longer carrying the spray directly to the ground plane. Above this critical speed the spray is seen to become suspended in the air behind the Unmanned Aerial System. This behaviour makes realistic simulation more difficult, as details of the ambient turbulence conditions would be needed to model the subsequent spray transport. The reliance on turbulence to transport the spray is undesirable from a practical point of view due to the increased likelihood of significant spray drift

mPneumonia: Development of an Innovative mHealth Application for Diagnosing and Treating Childhood Pneumonia and Other Childhood Illnesses in Low-Resource Settings

<div><p>Pneumonia is the leading infectious cause of death in children worldwide. Each year, pneumonia kills an estimated 935,000 children under five years of age, with most of these deaths occurring in developing countries. The current approach for pneumonia diagnosis in low-resource settings—using the World Health Organization Integrated Management of Childhood Illness (IMCI) paper-based protocols and relying on a health care provider’s ability to manually count respiratory rate—has proven inadequate. Furthermore, hypoxemia—a diagnostic indicator of the presence and severity of pneumonia often associated with an increased risk of death—is not assessed because pulse oximetry is frequently not available in low-resource settings. In an effort to address childhood pneumonia mortality and improve frontline health care providers’ ability to diagnose, classify, and manage pneumonia and other childhood illnesses, PATH collaborated with the University of Washington to develop “mPneumonia,” an innovative mobile health application using an Android tablet. mPneumonia integrates a digital version of the IMCI algorithm with a software-based breath counter and a pediatric pulse oximeter. We conducted a design-stage usability field test of mPneumonia in Ghana, with the goal of creating a user-friendly diagnostic and management tool for childhood pneumonia and other childhood illnesses that would improve diagnostic accuracy and facilitate adherence by health care providers to established guidelines in low-resource settings. The results of the field test provided valuable information for understanding the usability and acceptability of mPneumonia among health care providers, and identifying approaches to iterate and improve. This critical feedback helped ascertain the common failure modes related to the user interface design, navigation, and accessibility of mPneumonia and the modifications required to improve user experience and create a tool aimed at decreasing mortality from pneumonia and other childhood illnesses in low-resource settings.</p></div

Demographic characteristics of study participants.

Demographic characteristics of study participants.</p

Factors influencing occupational injuries among study participants.

Factors influencing occupational injuries among study participants.</p

S1 Dataset -

BackgroundEmergency Medical Technicians (EMTs) are the primary providers of prehospital emergency medical services. The operations of EMTs increase their risks of being exposed to occupational injuries. However, there is a paucity of data on the prevalence of occupational injuries among EMTs in sub-Saharan Africa. This study, therefore, sought to estimate the prevalence and determinants of occupational injuries among EMTs in the northern part of Ghana.MethodsA cross-sectional study was conducted among 154 randomly recruited EMTs in the northern part of Ghana. A pre-tested structured questionnaire was used to collect data on participants’ demographic characteristics, facility-related factors, personal protective equipment use, and occupational injuries. Binary and multivariate logistic regression analyses with a backward stepwise approach were used to examine the determinants of occupational injuries among EMTs.ResultsIn the 12 months preceding data collection, the prevalence of occupational injuries among EMTs was 38.6%. Bruises (51.8%), and sprains/strains (14.3%) were the major types of injuries reported among the EMTs. The key determinants of occupational injury among EMTs were male sex (AOR: 3.39, 95%CI: 1.41–8.17), an absence of a health and safety committee at the workplace (AOR: 3.92, 95%CI: 1.63–9.43), absence of health and safety policy at the workplace (AOR: 2.76, 95%CI: 1.26–6.04) and dissatisfaction with health and safety measures at the workplace (AOR: 2.51, 95%CI: 1.10–5.71).ConclusionIn the twelve months before to the data collection for this study, the prevalence of occupational injuries among EMTs of the Ghana National Ambulance Service was high. The creation of health and safety committees, the creation of health and safety rules, and the strengthening of current health and safety procedures for EMTs are all possible ways to lessen this.</div

Occupational injury, type, causes and PPE use among study participants.

Occupational injury, type, causes and PPE use among study participants.</p

mPneumonia Prototype Task Analysis Summary: Critical Errors = Errors Made Without Noticing.

<p>Abbreviations: DD = day; IMCI = Integrated Management of Childhood Illness; MM = month; RR = respiratory rate; YYYY = year.</p><p>mPneumonia Prototype Task Analysis Summary: Critical Errors = Errors Made Without Noticing.</p

mPneumonia Prototype Initial Responses.

<p>Note: 1–Strongly disagree; 2–Disagree; 3–Neither agree nor disagree; 4–Agree; 5–Strongly agree.</p><p>mPneumonia Prototype Initial Responses.</p

mPneumonia Prototype Task Analysis Summary: Noncritical Errors = Errors Almost Made, or Made and Corrected Appropriately.

<p>mPneumonia Prototype Task Analysis Summary: Noncritical Errors = Errors Almost Made, or Made and Corrected Appropriately.</p

Additional file 2: of Health service provider education and/or training in infant male circumcision to improve short- and long-term morbidity outcomes: protocol for systematic review

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