Factors associated with food workers working while experiencing vomiting or diarrhea

This study sought to determine the frequency with which food workers said they had worked while experiencing vomiting or diarrhea, and to identify restaurant and worker characteristics associated with this behavior. We conducted interviews with food workers (n=491) and their managers (n=387) in the nine states that participate in the Centers for Disease Control and Prevention's Environmental Health Specialists Network. Restaurant and worker characteristics associated with repeatedly working while experiencing vomiting or diarrhea were analyzed via multivariable regression. Fifty-eight (11.9%) workers said they had worked while suffering vomiting or diarrhea on two or more shifts in the previous year. Factors associated with workers having worked while experiencing vomiting or diarrhea were (i) high volume of meals served, (ii) lack of policies requiring workers to report illness to managers, (iii) lack of on-call workers, (iv) lack of manager experience, and (v) workers of the male gender. Our findings suggest that policies that encourage workers to tell managers when they are ill and that help mitigate pressures to work while ill could reduce the number of food workers who work while experiencing vomiting or diarrhea.     

Role of bond thickness on adhesive failure

An analytical, numerical and experimental program is described which establishes the basic fracture mechanics properties of an adhesive joint. A finite element analysis of a homogeneous finite tapered double cantilever beam is first presented and the results compared with elasticity and strength of materials solutions. Using analytical results developed in another paper, a finite bond line thickness correction factor is introduced to determine the crack tip stress intensity factor as a function of crack length. An experimental program is described wherein the crack tip stress intensity factor for the cantilever beam adhesive joint is measured by the compliance method and the results compared with those obtained by analytical and numerical methods. Finally, the critical value of the adhesive crack tip stress intensity factor is determined using the analytical and experimental techniques presented.     

Photochemical degradation of glassy polyesters of low softening point

The photodegradation of polyesters prepared by the reaction of o-phthalic, adipic, and “dimer” acids with ethylene glycol has been studied. The polyesters softened at temperatures in the range of 25–50°C. Polymer films were irradiated in air by means of a medium pressure mercury lamp and the extent of formation of COOH groups determined by infrared spectroscopy. The films were also irradiated in vacuo and in air by means of a high-pressure mercury lamp, and the volatile products, consisting mainly of carbon monoxide and carbon dioxide, were determined by gas chromatography. The results are interpreted in terms of simultaneous Norrish type I and type II decompositions of the polyesters. The type I process accounts for the formation of carbon monoxide and carbon dioxide in the absence of air. The enhanced yield of carbon dioxide in irradiations performed in air is ascribed to the formation of hydroperoxide which undergoes further photolysis. The type II process accounts for the formation of COOH groups. The photodegradation of these glassy polyesters parallels that of crystalline poly(ethylene terephthalate) and is relatively unaffected by changes in composition of the aromatic polyester.     

A GENERAL APPROACH FOR ANALYZING THE ARBITRARY MOTION OF A CIRCULAR DISK IN A STOKES FLOW

A concise analytic method is developed to investigate the arbitrary motion of a circular disk through an unbounded fluid satisfying Stokes equation. Four elementary motions are considered within the same mathematical framework: broadside translation, edgewise translation, in-plane rotation and out-of-plane rotation of a disk. Stokes equations are reduced to a set of dual integral expressions relating the velocity and traction in the plane of the disk. The dual integral equations are solved exactly for each motion and lead, in turn, to closed-form analytical expressions for the velocity and pressure fields. Although many of these results have been previously reported, the approach described here unifies the analysis of the four different motions and presents a straightforward solution technique.