25. Isolation and Identification of Bacteria from Therapeutic Ball Pits Located in Hospital Settings

It is known that bacteria can be found on commercial ball pits. Due to ball pits moist, dark, warm environments, bacteria flourish, increasing risk of transmission. No study has been conducted on clinical therapeutic ball pits. These ball pits may be used constantly, yet no protocol exists on sanitation, or its frequency. Infrequent cleanings allow bacteria to reproduce to potentially infectious levels. Risk increases if the individual has lesions, abrasions, or is immunocompromised. An understanding in microbial communities of therapeutic ball pits and proper cleaning protocol was sought. A study was conducted using six clinical ball pits in Georgia. Sampling consisted of selecting random balls, swabbing five locations (four corners and center), and different strata (depths). Samples were plated on tryptic soy agar (TSA) plates, and incubated for twenty-four hours at 33 °C. Afterwards, microbial colonies were tallied. Colonies were identified using the Biolog GEN III Bacterial Identification System. Differences were found between clinics and the amount of colony forming units (CFU) from each sample. Clinic B had the least amount of CFU with 36% of balls having less than 3.0x101 CFU, and 7% with greater than 3.0x104 colonies. Clinic D had the largest CFU with 93% of balls having greater than 3.0x104 CFU. Potential opportunistic pathogens identified are Enterococcus faecalis, Acinetobacter lwoffii, Paoultella terrigena, Psychrobacter immobilis, Paenibacillus xylanilyficus, Klebsiella variicola, and Moraxella caprae. Balls with floor exposure had the most CFU; middle stratum balls had the least CFU; and balls with surface exposure had the second highest CFU

Real World Assessment of an Auto-parametric Electromagnetic Vibration Energy Harvester

The convention within the eld of vibration energy harvesting (VEH) has revolved around designing resonators with natural frequencies that match single fixed frequency sinusoidal input. However, real world vibrations can be random, multi-frequency, broadband and time-varying in nature. Building upon previous work on auto-parametric resonance, the fundamentally different approach allows multiple axes vibration and has the potential to achieve higher power density as well as wider operational frequency bandwidth. This paper presents the power response of a packaged auto-parametric VEH prototype (practical operational volume 126 cm^3) towards various real world vibration sources including vibration of a bridge, a compressor motor as well as an automobile. At auto-parametric resonance (driven at 23.5 Hz and 1 grms), the prototype can output a peak of 78.9 mW and 4.5 Hz of -3dB bandwidth. Furthermore, up to ~1 mW of average power output was observed from the harvester on the Forth Road Bridge. The harvested electrical energy from various real world sources were used to power up a power conditioning circuit, a wireless sensor mote, a MEMS (micro-electromechanical system) accelerometer and other low power sensors. This demonstrates the concept of self-sustaining vibration-powered wireless sensor systems in real world scenarios, to potentially realise maintenance-free autonomous structural health and condition monitoring.This work was supported by EPSRC (grant EP/L010917/1) and the Cambridge Centre for Smart Infrastructure and Construction

The Suprafroth (Superconducting Froth)

The structure and dynamics of froths have been subjects of intense interest due to the desire to understand the behaviour of complex systems where topological intricacy prohibits exact evaluation of the ground state. The dynamics of a traditional froth involves drainage and drying in the cell boundaries, thus it is irreversible. We report a new member to the froths family: suprafroth, in which the cell boundaries are superconducting and the cell interior is normal phase. Despite very different microscopic origin, topological analysis of the structure of the suprafroth shows that statistical von Neumann and Lewis laws apply. Furthermore, for the first time in the analysis of froths there is a global measurable property, the magnetic moment, which can be directly related to the suprafroth structure. We propose that this suprafroth is a new, model system for the analysis of the complex physics of two-dimensional froths