Atmospheric pressure plasma pretreatment of sugarcane bagasse: the influence of biomass particle size in the ozonation process.

Atmospheric pressure O2 plasma was used to produce ozone in order to treat sugarcane bagasse as a function of particle sizes. The fixed bagasse moisture content was 50%. The delignification efficiency had small improvement due to ozonation process as a function of particle size, varying from 75 up to 80%. Few amounts of hemicellulose were removed, but the ozonation has not been affected significantly with particle size variance as well (from 30 up to 35%). The cellulose presented some losses below 1.0 mm size (8-15%) which was an unexpected result. The conversion of cellulose content into free sugar has shown a significant increase as the particle size has diminished as well. The best condition of the bagasse particle size was for 0.08 mm. For this case, a great quantity of cellulose (78.8%) was converted into glucose. Optical absorption spectroscopy was applied to determine ozone concentrations in real time where the samples with typical bagasse particle sizes equal or below to 0.5 mm had shown a better absorption of ozone in comparison with greater particle size samples.

Atmospheric pressure plasma pretreatment of sugarcane bagasse: the influence of moisture in the ozonation process.

Sugarcane bagasse samples were pretreated with ozone via atmospheric O2 pressure plasma. A delignification efficiency of approximately 80 % was observed within 6 h of treatment. Some hemicelluloses were removed, and the cellulose was not affected by ozonolysis. The quantity of moisture in the bagasse had a large influence on delignification and saccharification after ozonation pretreatment of the bagasse, where 50 % moisture content was found to be best for delignification (65 % of the cellulose was converted into glucose). Optical absorption spectroscopy was applied to determine ozone concentrations in real time. The ozone consumption as a function of the delignification process revealed two main reaction phases, as the ozone molecules cleave the strong carbon-carbon bonds of aromatic rings more slowly than the weak carbon-carbon bonds of aliphatic chains.

Effects of a participatory ergonomics team among hospital orderlies.

BACKGROUND: High rates of work-related injuries are seen among health care workers involved in lifting and transferring patients. We studied the effects of a participatory worker-management ergonomics team among hospital orderlies. METHODS: This prospective intervention trial examined work injuries and other outcomes before and after the intervention, with other hospital employees used as a concurrent control. All orderlies in a 1,200-bed urban hospital were studied using passively collected data (mean employment during study period 100-110 orderlies); 67 orderlies (preintervention) and 88 orderlies (postintervention) also completed a questionnaire. The intervention was the formation of a participatory ergonomics team with three orderlies, one supervisor, and technical advisors. This team designed and implemented changes in training and work practices. RESULTS: The 2-year postintervention period was marked by decreased risks of work injury (RR = 0.50, 95% CI 0.35-0.72), lost time injury (RR = 0.26, 95% CI 0.14-0.48), and injury with three or more days of time loss (RR = 0.19, 95% CI 0.07-0.53). Total lost days declined from 136.2 to 23.0 annually per 100 full-time worker equivalents (FTE). Annual workers' compensation costs declined from $237/FTE to $139/FTE. The proportion of workers with musculoskeletal symptoms declined and there were statistically significant improvements in job satisfaction, perceived psychosocial stressors, and social support among the orderlies. CONCLUSION: Substantial improvements in health and safety were seen following implementation of a participatory ergonomics program.

Implementing participatory ergonomics teams among health care workers.

Three participatory ergonomics teams have been established among healthcare workers in a metropolitan medical center. Three teams, consisting of orderlies, intensive care unit nurses, and laboratory workers, were selected to provide a diversity of work activities and educational backgrounds. The effectiveness of these teams was assessed by observations of team interactions, by team members' perceptions of their effectiveness, and by the teams' success in identifying problems and implementing solutions. After 1 year, one of the three groups has been highly effective by these measures. To varying degrees, the groups encountered competing time demands and obstacles in implementing solutions within current administrative structures. For some groups of health care workers, participatory ergonomics teams seem to be an effective strategy to improve health and safety. This approach may not be feasible in all areas of health care, especially in high-demand clinical areas where patient needs may take precedence over the safety of health care workers.

Relationships among grip strength, work capacity, and recovery.

The relationship between strength, fatigue, and work capacity is a central issue for occupational rehabilitation. Musculoskeletal impairments often are expressed functionally as a loss of strength. For work tasks that require strength, such impairments may have a detrimental effect on work capacity that is sufficient to be disabling. How important is strength as a component of work capacity? How do work capacity and strength affect recovery time from repetitive forceful upper extremity work ? A sample of 40 healthy subjects comprised of 20 males and 20 females was studied in a model that used the isotonic strength of each subject to set exercise levels for subsequent forceful repetitive gripping tasks. Resistance levels of 75%, 50%, and 25% of maximum were used for one-per-second repetitions until the subject could not maintain that pace. Isometric grip strength was measured after 1 minute of rest and after 5, 10, and 20 minutes. Results indicate that males and females do not differ in terms of their rate of recovery and that the best predictor of recovery time is the immediate measurement of strength loss following cessation of work activity.

Pulmonary embolism in total joint arthroplasty.

With a greater understanding of the prevention of thromboembolic complications, the incidence of fatal pulmonary embolism after total joint arthroplasty has declined. Although much of our knowledge is centered around deep vein thrombosis and its use as a marker for thromboembolic complications, little is known about the natural history of both symptomatic and asymptomatic pulmonary embolism. Although differing methods of prophylaxis have shown some success, the ideal agent has yet to be discovered. The use of serial lung scanning has shown great use in the diagnosis of pulmonary embolism. Additional studies using effective diagnostic tools are needed to evaluate the risk of recurrent embolism. Only then can the duration of treatment and prophylaxis be determined. Despite the many unanswered questions, the following conclusions can be drawn: (1) fatal pulmonary emboli are a preventable complication of total joint arthroplasty; (2) fatal emboli are often preceded by small and frequently asymptomatic emboli; (3) detection and appropriate therapeutic measures for asymptomatic emboli are possible with the use of serial lung scans and judicious use of pulmonary angiography; and (4) low-dose coumadin has proven to be the most effective agent in lowering the risk of asymptomatic, symptomatic, and fatal pulmonary emboli.

The intensity of auditory warning tones in the automobile environment: detection and preference evaluations.

A variety of auditory warning tones was evaluated to determine generally appropriate intensity levels for presentation in the automobile environment. Twenty-four subjects listened to tones presented at several intensity levels under three background noise conditions recorded in actual vehicles: relatively quiet (35 mile/h (56 km/h), smooth road), relatively loud (55 mile/h (89 km/h), rough road), and radio (35 mile/h (56 km/h), smooth road, and radio broadcast). Data were gathered on the minimum intensity level (in decibels (dB) above the masked threshold (MT) required to achieve a consistent criterion detection rate, as well as the preferred tone intensity level (in dB above the MT) in each background noise condition. The preferred levels were louder than those required to achieve the detection criterion in both the relatively loud and quiet background noise conditions; thus, the preferred levels are the recommended levels under those conditions. This was not the case in the radio condition; therefore, it is recommended that future research efforts evaluate the effects of automatically muting the radio/stereo system when important auditory warning tones are being presented.