Evaluation of ergonomic adjustments of catering carts to reduce external pushing forces

An existing standard catering cart was compared with two prototypes for pushbar and castor design. The first objective of this study was to find out which cart was accompanied with the lowest manually exerted external forces in pushing in a straight way and in pushing a 90 turn. The second objective was to explore effects of the pushbar and castor design of the carts. In the initial and ending phase, the prototypes were accompanied with higher exerted forces compared with the standard catering cart. In pushing straight. the reversed start position of the bigger castors of the prototypes hampered a fluent acceleration and caused higher initial forces. In decelerating, the lower rolling friction of the bigger castors required higher forces to stop the prototypes compared to the standard cart. During the sustained phase, the prototype carts were more favourable. Effects of pushbar and castor design were studied during a turn. The vertical pushbars of the prototypes resulted in lower time-integrated pushing forces. Providing an axis of rotation for turning activities by means of a fixed wheel was proven to be advantageous.     

Psychophysical assessments of image-sensor fused imagery

The goal of this study was to determine the perceptual advantages of multiband sensor-fused (achromatic and chromatic) imagery over conventional single-band nighttime (image-intensified and infrared) imagery for a wide range of visual tasks, including detection, orientation, and scene recognition. Participants were 151 active-duty military observers whose reaction time and accuracy scores were recorded during a visual search task. Data indicate that sensor fusion did not improve performance relative to that obtained with single-band imagery on a target detection task but did facilitate object recognition, judgments of spatial orientation, and scene recognition. Observers' recognition and orientation judgments were improved by the emergent information within the image-fused imagery (i.e., combining dominant information from two or more sensors into a single displayed image). Actual or potential applications of this research include the deployment of image-sensor fused systems for automobile, aviation, and maritime displays to increase operators' visual processing during low-light conditions.     

Relationship between maximum acceptable work time and physical workload

For safe job design, it is necessary to know the maximum acceptable work time (MAWT) for a given workload. The aim was to establish the relationship between MAWT and physical workload. Cycling tests at six different work rates relative to personal maximum working capacity were performed by 12 young adults in the laboratory. The oxygen uptake (VO(2)) in the per cent maximum aerobic capacity (%VO(2max)), relative heart rate (RHR) and relative oxygen uptake (RVO(2)) were collected throughout the test. MAWT was determined by observing the heart rate data during the test. The results showed that MAWT was negatively correlated with %VO(2max), RHR and RVO(2) (p < 0.01). Three exponential regression models were obtained and all their R(2) > 0.80. These models suggest that long-hour shifts (> 10 h) should assign a lower work intensity than for an 8-h workday. It is also logical that the workload limit for a 4-h work shift could be set at about 10% VO(2max) higher than the suggested limit for an 8-h workday.     

MLP无损压缩编码基本原理

英国子午线公司的无损压缩技术(Meridian Lossless Packing),简称MLP,是一种无损编码系统,它取代了最初的线性脉冲编码调制(Linear PCM),被广泛应用在高品质数字音频数据处理方面。目前,高品质音频就意味着高采样率、大采样字长和多通道。本文介绍了MLP系统,可以看作是对Gerzon,M．A．,Craven,EG．, Stuart,J．R．,Law,M．和Wilson,R．J．编写的《MLP无损压缩系统》一书的简要概括。     

Setting thresholds for quality indicators derived from MDS data for nursing home quality improvement reports: an update

BACKGROUND: Determining meaningful thresholds to reinforce excellent performance and flag potential problem areas in nursing home care is critical for preparing reports for nursing homes to use in their quality improvement programs. This article builds on the work of an earlier panel of experts that set thresholds for quality indicators (QIs) derived from Minimum Data Set (MDS) assessment data. Thresholds were now set for the revised MDS 2.0 two-page quarterly form and Resource Utilization Groups III (RUGS III) quarterly instrument. SETTING THRESHOLDS: In a day-long session in October 1998, panel members individually determined lower (good) and upper (poor) threshold scores for each QI, reviewed statewide distributions of MDS QIs, and completed a follow-up Delphi of the final results. REPORTING MDS QIS FOR QUALITY IMPROVEMENT: The QI reports compiled longitudinal data for all residents in the nursing home during each quarter and cumulatively displayed data for five quarters for each QI. A resident roster was provided to the nursing home so that the quality improvement team could identify the specific residents who developed the problems defined by each QI during the last quarter. Quality improvement teams found the reports helpful and easy to interpret. SUMMARY AND CONCLUSIONS: As promised in an earlier report, to ensure that thresholds reflect current practice, research using experts in a panel to set thresholds was repeated as needed. As the MDS instrument or recommended calculations for the MDS QIs change, thresholds will be reestablished to ensure a fit with the instrument and data.     

The influence of speed, grade and mass during simulated off road bicycling

The purpose of this investigation was to examine the effects of bicycle mass, speed, and grade on oxygen consumption (VO2), heart rate (HR), and ratings of perceived exertion (RPE) during a simulated off-road riding paradigm. Nine adult subjects with mean +/- SD age, mass, and VO2 max of 26.1 +/- 5.6 years, 71.7 +/- 7.5 kg, 56.6 +/- 5.2 ml x kg(-1) x min(-1) respectively, were trained to ride a fully suspended Trek Y-22 mountain bike on a treadmill with a 3.8 cm bump affixed to the belt. Riders completed a maximum of nine separate trials encompassing three different bike masses (11.6, 12.6 and 13.6 kg), 3 speeds (2.7, 3.6 and 4.5 m x s(-1)), and 3 grades (0, 2.5, and 5%). Throughout a trial, bike mass and speed remained constant while riding grade was increased every 5 min. During simulated off-road riding on a fully suspended mountain bike, increases in speed and grade significantly increased VO2, heart rate, and RPE. Increases in bike mass had no significant effects on VO2, heart rate or RPE. In addition, speed and grade changes interacted to differentially affect VO2, heart rate, and RPE at all speeds and grades.     

Work organization and ergonomics

This paper examines the impact of sociotechnical and business trends on work organization and ergonomics. This analysis is performed with the use of Balance Theory (Smith and Carayon-Sainfort, Int. J. Ind. Ergon. 1989, 4, 67–79. The impact on work organization and the work system of the following sociotechnical and business trends is discussed: re-structuring and re-organizing of companies, new forms of work organization, workforce diversity, and information and communication technology. An expansion of Balance Theory, from the design of work systems to the design of organizations, is discussed. Finally, the issue of change is examined. Several elements and methods are discussed for the design of change processes.     

Efficacy evaluation of the molasses supplementation in normal and depleted rats diet

Molasses, a sugar cane by-product, has been consumed in Brazil since colonial times. The efficacy of molasses added to the diet of normal and depleted laboratory animals on growth and hemoglobin was tested. Forty weaning males rats, of 21 days of age, were divided into four groups of ten animals: Control (casein diet with 10.14% protein); Molasses (casein diet with 10.14% protein and 12.50% molasses); Depleted Control and Depleted Molasses, the later two submitted to protein depletion for the first 7 days of the trial. Animals were weighed at weaning (initial weight) and at the end of the experiment (final weight) and were fed the experimental rations and water ad libitum for 28 days (normal animals) and 21 days (depleted animals). Consumption was registered in order to calculate the Food Efficiency Ratio. At the end, animals fasted for 10 hours, killed and blood was collected by cardiac puncture to determine hemoglobin levels. Weight gain in all groups did not show statistically significant differences. Molasses fed animals presented a small, but not significant increase in hemoglobin levels, compared to the control groups. Considering the possible deleterious effects of a high sugar diet, that can originate furfural during food processing, it is necessary to conduct more studies to evaluate the utilization of these products for human consumption.     

Modular phospholane ligands in asymmetric catalysis

This Account outlines the preparation and application of a class of phosphine ligands based upon the trans-2,5-disubstituted phospholane moiety. The modular nature of these ligands has allowed facile variation of both phospholane substituent and backbone structure, thus providing access to a series of ligands. Bidentate bis(phospholane) ligands have been found to be very useful in asymmetric catalytic hydrogenation reactions. In particular, we highlight the versatility of highly efficient bis(phospholane)rhodium catalysts that allow enantioselective hydrogenation to produce a diverse range of compounds containing C-N, C-O, and C-C stereogenic centers.