Coronavirus PPE: a positive pressure hood assembled from ubiquitous, low-cost materials

A positive pressure protective hood system was purposefully constructed only from materials commonly found worldwide, including bendable aluminum mesh, elastic head straps, velcro tape, a plastic sheet, a furnace filter and two computer central processing unit (CPU) cooling fans. The practical advantages of this system are that the materials are readily available in the inventories of most electronics and hardware outlets, ease of assembly (particularly if choosing to employ 3D printing for the fan enclosure and/or making several units at once with a defined workflow), and high probability of the materials being available in current or prospective personal protective equipment (PPE)-deplete regions. An experiment with identical fire detectors showed adequate inner isolation of the hood prototype from paper combustion particulates, which have a size range slightly smaller than putative coronavirus aerosols, for at least 90 seconds. The theoretical advantages of this system include significant reduction in healthcare provider exposure to coronavirus-containing respiratory fomites, respiratory droplets and aerosols (vs. traditional static masks and shields) during high risk procedures such as endotracheal intubation or routine care of an upright and coughing patient. Additionally, the assembly eliminates contact exposure to coronavirus fomites due to whole-head coverage from a hood system.

EVALUATION OF FLAT SHALLOW CAVITY SOLAR COLLECTOR INSERTED WITH POROUS LAYER

The evaluation of flat shallow cavity solar collector inserted with porous substrate was investigated experimentally and numerically. The aim of this work is to improve the thermal performance of flat plate solar collectors using enhanced heat transfer technique. Porous media were made of multilayer of aluminum mesh to form a porous layer of thickness 25 mm inserted under the absorber plate with porosity of 0.9 and permeability of 84.87. The solar collector was installed in Baghdad south facing at a fixed tilt angle (45°). Three types of solar collector have been designed and constructed namely solar collector made of shallow enclosure (model I), solar collector made of shallow enclosure inserted partially with porous layer (model II) and solar collector with channels of corrugated channels inserted partially with porous layer (model III). The results of parametric study of model III in case of continuous operating showed that the maximum average water temperature difference of water between collector outlet and inlet exceeds (7.21°C) and the maximum outlet temperature exceeds (50°C) at solar noon for (November, and December 2013). The thermal efficiency for collector model III was ranged from 47.52% to 52.2%, while that for model I was ranged (33.5% to 42.3%) under the same environmental conditions.

Modified Tray with Mesh Design for the Management of Flabby Ridge: A Case Report

Flabby ridge is an excessive movable fibrous tissue, usually affecting the maxillary and mandibular edentulous ridges. It is a typical finding frequently observed in the maxillary anterior region. It usually occurs when natural teeth oppose an edentulous ridge or in long-term denture wearers. The management of flabby ridges includes surgical intervention, implant-retained prostheses, and conventional dentures fabricated using the modified impression technique. This case report depicts a modified technique with the utilization of an aluminum mesh double tray and polyvinylsiloxane impression material for the management of a flabby ridge in the maxillary arch.