field study was conducted to evaluate seat designs on shuttle cars. Eight operators R A participated in evaluating seat designs on the basis of perceived levels of vehicle jarring/jolting and discomfort. Researchers also measured the levels of vehicle jarring/jolting. Four basic seat designs were compared on low and mid-coal seam shuttle cars during production operations at two underground coal...

We discuss changing the variable ordering for a regular chain in positive dimension. This quite general question has applications going from implicitization problems to the symbolic resolution of some systems of differential algebraic equations. We propose a modular method, reducing the problem to dimension zero and using Newton-Hensel lifting techniques. The problems raised by the choice of th...

The National Institute for Occupational Safety and Health (NIOSH) created the NIOSH Science Blog to provide a new way to further the Institute’s long-standing commitment to optimizing two-way communication with partners, stakeholders, and the public. The blog provides an opportunity for NIOSH scientists and stakeholders to present ideas to each other while engaging in robust scientific discussi...

let $m$ be a right module over a ring $r$, $tau_m$ a preradical on $sigma[m]$, and$ninsigma[m]$. in this note we show that if $n_1, n_2in sigma[m]$ are two$tau_m$-lifting modules such that $n_i$ is $n_j$-projective ($i,j=1,2$), then $n=n_1oplusn_2$ is $tau_m$-lifting. we investigate when homomorphic image of a $tau_m$-lifting moduleis $tau_m$-lifting.

Muscle pain is often experienced by workers who have to move repeatedly and/or forcibly. The cumulative trauma disorder that results from repetitive movements is difficult to anticipate and prevent. The present study uses a rodent model to: (1) determine the factors which produce dysfunctional muscles, (2) document changes in the matrix and myofibers which lead to pathologic muscles, and (3) st...

In lifting tasks involving manual material handling the coupling component relates to the quality of the hand-toobject interface (grip). Good coupling is theorized to reduce lifting and grip stress, whereas poor coupling is theorized to increase lifting and grip stress. Choosing to lift with one hand is a decision often made by the worker. Understanding the metabolic demand of one-handed liftin...

controlling exposures of workers to nitrous oxide (N2O) during the administration of anesthetic gas in medical, dental, and veterinary operatories. NIOSH concluded in 1977 that exposure to N2O causes decreases in mental performance, audiovisual ability, and manual dexterity [NIOSH 1977b]. A recent study of workers [Rowland et al. 1992] and several experimental animal studies [Corbett et al. 197...

Silica, or silicon dioxide (SiO2), is a group IV metal oxide, which naturally occurs in both crystalline and amorphous forms (i.e. polymorphic; NTP, 2005). The various forms of crystalline silica are: α-quartz, β-quartz, α-tridymite, β-tridymite, α-cristobalite, β-cristobalite, keatite, coesite, stishovite, and moganite (NIOSH, 2002). The most abundant form of silica is α-quartz, and the term q...