Effectiveness of a personalized ventilation system in reducing personal exposure against directly released simulated cough droplets

The inhalation intake fraction was used as an indicator to compare effects of desktop personalized ventilation and mixing ventilation on personal exposure to directly released simulated cough droplets. A cough machine was used to simulate cough release from the front, back, and side of a thermal manikin at distances between 1 and 4 m. Cough droplet concentration was measured with an aerosol spectrometer in the breathing zone of a thermal manikin. Particle image velocimetry was used to characterize the velocity field in the breathing zone. Desktop personalized ventilation substantially reduced the inhalation intake fraction compared to mixing ventilation for all investigated distances and orientations of the cough release. The results point out that the orientation between the cough source and the breathing zone of the exposed occupant is an important factor that substantially influences exposure. Exposure to cough droplets was reduced with increasing distance between cough source and exposed occupant.     

Software engineering practices and Simulink: bridging the gap

International Journal on Software Tools for Technology Transfer - Although widely used in embedded systems design, Matlab/Simulink is not considered a state-of-the-art design environment by the...     

Performance evaluation of the coupling of a desktop personalized ventilation air terminal device and desk mounted fans

The performance of a coupled system of the Desktop Personalized Ventilation Air Terminal Device (DPV ATD) and desk mounted fans (DMF) was examined in a field environmental chamber. Cooling effect was evaluated using manikin-based equivalent temperature (Teq,), of each of the 26 body segments of a breathing thermal manikin (BTM) and personal exposure effectiveness (PEE) was used as an indicator for effectiveness of ventilation. Computational fluid dynamics (CFD) was used to examine the velocity field generated around BTM to provide better understanding of the relationship between air patterns generated and convective cooling effect on each of the body segments produced by DPV ATD coupled with DMF. Four different positions of DPV ATD were examined: two positions each in front and on the side of the BTM. Measurements were conducted at ambient temperature of 26 °C and PV air temperature of 23 °C at a flow rate of 10 L/s. The results indicate that coupling of DPV ATD and DMF distributes cooling more uniformly across BTM surfaces and therefore has the potential to reduce risk of draft discomfort as compared to usage of DPV ATD alone. Personalized exposure effectiveness was increased in 3 of the positions examined when the coupled system was used.     

Repository mining for changes in Simulink and Stateflow models

Software and Systems Modeling - Model-Based Development (MBD) is widely used for embedded controls development, with MATLAB/Simulink/Stateflow being one of the most used development environments in...     

Improving the holographic sensitivity of dichromated gelatin in the blue-green part of the spectrum by sensitization with xanthene dyes

The holographic properties of dichromated gelatin (DCG) sensitized with various xanthene dyes were studied, and results are reported. The sensitivity of dyed DCG in the green part of the spectrum compared with that of pure DCG (215 mJ/cm(2)) was significantly improved by addition of Rhodamine 6G (140 mJ/cm(2)) or Erythrosin B (90 mJ/cm(2)). Diffraction gratings were recorded with a He-Ne laser at 543.5 nm. The maximum diffraction efficiency was found to be 32% at normal incidence of the readout beam; it was 80% at the Bragg angle.     

Luminescence-Based Spectroelectrochemical Sensor for [Tc(dmpe)(3)](2+/+) (dmpe = 1,2-bis(dimethylphosphino)ethane) within a Charge-Selective Polymer Film

A spectroelectrochemical sensor consisting of an indium tin oxide (ITO) optically transparent electrode (OTE) coated with a thin film of partially sulfonated polystyrene-blockpoly(ethylene-ran-butylene)-block-polystyrene (SSEBS) was developed for [Tc(dmpe)(3)](+) (dmpe = 1,2-bis(dimethylphosphino)ethane). [Tc(dmpe)(3)](+) was preconcentrated by ion-exchange into the SSEBS film after a 20 min exposure to aqueous [Tc(dmpe)(3)](+) solution, resulting in a 14-fold increase in cathodic peak current compared to a bare OTE. Colorless [Tc(dmpe)(3)](+) was reversibly oxidized to colored [Tc(dmpe)(3)](2+) by cyclic voltammetry. Detection of [Tc(dmpe)(3)](2+) was accomplished through emission spectroscopy by electrochemically oxidizing the complex from nonemissive [Tc(dmpe)(3)](+) to emissive [Tc(dmpe)(3)](2+). The working principle of the sensor consisted of electrochemically cycling between nonemissive [Tc(dmpe)(3)](+) and emissive [Tc(dmpe)(3)](2+) and monitoring the modulated emission (λ(exc) = 532 nm; λ(em) = 660 nm). The sensor gave a linear response over the concentration range of 0.16-340.0 μM of [Tc(dmpe)(3)](2+/+) in aqueous phase with a detection limit of 24 nM.     

Three-dimensional analysis of the effect of human movement on indoor airflow patterns

Human activity is known to leave significant effects on indoor airflow patterns. These patterns are carefully designed for many facilities such as cleanrooms, pharmaceutical settings, and healthcare environments, where human-induced wakes contribute to the transport of contaminants. Therefore, the knowledge about these wakes as it relates to indoor air quality is critical. As a result, a series of experiments were conducted in a controlled chamber to study the three-dimensional effects of true human walking on airflow. Experiments were designed to capture the effect of human walking under three different flow conditions, and for two different walking schemes. The results show that the effect of walking on the airflow is not negligible and can sustain up to 10 seconds after the moving body has passed. Walking on a straight line creates significant change in the velocity normal to the walking path and vertical to the plane of walking movement. These changes were detectable till 1.0 m away from the walking track. Also, the similarity between airflow patterns of walking once and twice illustrated a promising opportunity of predicting the flow patterns of random walk from a set of base cases.     

Development of a prospective isopropyl alcohol-loaded pharmaceutical base using simultaneous in vitro/in vivo characterization methods of skin performance

Context: Approaching of pharmaceutical and cosmetic industries in some aspects inevitably influence formulation of topical pharmaceuticals, urging researchers to introduce novel excipients with proven benefits over traditional ones. In that context, alkyl polyglucosides (APG) emerge as prominent natural-origin emulsifiers with numerous favorable features (biodegradability, dermatological acceptability, desirable sensory properties).

Objective: To evaluate APG-stabilized bases (alone and upon addition of isopropyl alcohol) and their impact on skin performance. A simultaneous in vitro/in vivo skin absorption study was conducted to evaluate whether the tape stripping technique could be recommended as an in vivo tool for skin penetration assessment during formulation optimization process.

Materials and methods: After a comprehensive physicochemical characterization, biopharmaceutical properties of APG-bases versus reference ones were assessed through a combined in vitro (release/permeation) and in vivo approach.

Results and discussion: Physicochemical characterization revealed substantial difference in structural ordering due to the formation of various mesomorphic phases. The enhancer-loaded APG base resulted in significantly higher drug levels at all depths into the stratum corneum, indicating that the selected enhancer along with specific colloidal structure has increased the extent of drug delivery.

Conclusion: Results recommend the investigated emulsifier for stabilization of topical drug delivery systems, not only for their ability to sustain the addition of isopropyl alcohol which proved to be a valuable enhancer, but also satisfactory skin absorption and tolerability when compared to samples stabilized by conventional emulsifier. Tape stripping proved to be a useful and yet inexpensive tool for in vivo trials, able to discriminate subtle differences in dermal availability.