Temporal trends in personal protective equipment (PPE) debris during the COVID-19 pandemic in Çanakkale (Turkey).

This study examines trends in PPE (masks, gloves) and disinfecting wipes over three years of the pandemic. The densities of discarded masks, wet wipes, and gloves (personal protective equipment: PPE), were quantified on the streets of Canakkale, Turkey during similar time periods in 2020, 2021 and 2022. Geotagged images of PPE on the streets and sidewalks were documented with a smartphone, while the track of an observer was recorded using a fitness tracker app along a 7.777 km long survey route in the city center, parallel to the Dardanelles Strait. A total of 18 surveys were conducted over three years, and the survey route was subdivided into three zones based on utilization patterns: pedestrian zone, traffic zone and a recreational park zone. The combined densities of all types of PPE density were high in 2020, lower in 2021 and highest in 2022. The within year trend showed an increase over the three study years. The average density of gloves declined from an initially high level in 2020, when the SARS-CoV-2 virus was thought to be transmitted by contact, to near zero in 2021 and to zero in 2022. Densities of wipes were similar in 2020 and 2021 and higher in 2022. Masks were initially difficult to procure in 2020, and their densities progressively increased during that year reaching a plateau in 2021 with similar densities in 2022. PPE densities were significantly lower in the pedestrian route relative to the traffic and park routes, which were not different from each other. The partial curfews implemented by the Turkish government and the effects of prevention measures taken on the PPE concentration in the streets are discussed along with the importance of waste management practices.

Integration of a surgical robotic arm to the connected operating room via ISO IEEE 11073 SDC.

PURPOSE: Since 2019, intraoperative networking with ISO IEEE 11073 SDC has, for the first time, enabled standardized multi-vendor data exchange between medical devices. For seamless plug-and-play integration of devices without previous configuration, further specifications for device profiles ("device specializations") on top of the existing core standards must be developed. These generic interfaces are then incorporated into the standardization process. METHODS: An existing classification scheme of robotic assistance functions is being adopted and used as a baseline to derive functional requirements for a universal interface for modular robot arms. Additionally, the robot system requires machine-machine interfaces (MMI) to a surgical navigation system and a surgical planning software in order to carry out its function. Further technical requirements are derived from these MMI. The functional and technical requirements motivate the design of an SDC-compatible device profile. The device profile is then assessed for feasibility. RESULTS: We present a new modeling of a device profile for surgical robotic arms intended for neurosurgery and orthopedic surgery. The modeling in SDC succeeds for the most part. However, some details of the proposed model cannot yet be realized within the framework of the existing SDC standards. Some aspects can already be realized, but could be better supported in the future by the nomenclature system. These improvements are being presented as well. CONCLUSION: The proposed device profile presents a first step toward a uniform technical description model for modular surgical robot systems. The current SDC core standards lack some functionality to fully support the proposed device profile. These could be defined in future work and then included in standardization efforts.

Damage cluster distributions in numerical concrete at the mesoscale.

We investigate the size distribution of damage clusters in concrete under uniaxial tension loading conditions. Using the finite-element method, the concrete is modeled at the mesoscale by a random distribution of elastic spherical aggregates within an elastic mortar paste. The propagation and coalescence of damage zones are then simulated by means of dynamically inserted cohesive elements. Dynamic failure analysis shows that the size distribution of damage clusters follows a power law when a system-spanning cluster is first observed, with an exponent close to that of percolation theory. This is found for a range of selected mesostructural parameters, material defects, and applied strain rates. In all cases, the system-spanning cluster occurs prior to the onset of local decohesion, a regime of crack nucleation and propagation, and eventual material failure. The resulting fully damaged crack surfaces after failure are found to be only weakly correlated with the percolated damage region structures.

Avalanches in dry and saturated disordered media at fracture.

This paper analyzes fracturing in inhomogeneous media under dry and fully saturated conditions. We adopt a central force model with continuous damage to study avalanche behavior in a two-dimensional truss lattice undergoing dilation. Multiple fractures can develop at once and a power-law distribution of the avalanche size is observed. The values for the power-law exponent are compared with the ones found in the literature and scale-free behavior is suggested. The fracture evolves intermittently in time because only some avalanches correspond to fracture advancement. A fully saturated model with continuous damage based on the extended Biot's theory is developed and avalanche behavior is studied in the presence of fluid, varying the fluid boundary conditions. We show that power-law behavior is destroyed when the fluid flux governs the problem. Fluid pressure behavior during intermittent crack tip advancement is studied for the continuous-damage fully saturated model. It is found that when mechanical loading prevails, the pressure rises when the crack advances, while when fluid loading prevails, the pressure drops when the crack advances.