A method for evaluation of manual work using synchronised video recordings and physiological measurements

Industrial interventions that focus on increased productivity may impair the ergonomics, on a workstation or individual level. This paper presents a method that characterises work time consumption and physical work load of manual work, using video recordings synchronised with physiological measurements of, e.g. muscular activity, and postures. The underlying idea was that it is possible to amalgamate technical and human aspects resulting in a synergetic evaluation. The method was developed through two case studies within the Swedish automotive industry, where manual materials handling was studied. A methodological result was that the synchronising procedure was sufficiently precise to allow work activities to be assigned significantly different levels of physical work load. These different levels may be used to predict physical work load in the design and change of production systems. It was concluded that the method is accurate enough to be a useful tool in industrial interventions.     

Methoxybutropate microencapsulation by gelatin-acacia complex coacervation

Microcapsules of methoxybutropate solid particles or of an oily saturated solution of the same drug were prepared by complex coacervation between gelatin and acacia and dried with three different methods: isopropanol addition, spray-drying, and freeze-drying. Successively, microparticles were analyzed by infrared thermobalance, ultraviolet (UV) spectroscopy, optical and scanning electron microscopy, and sieves to find out parameters such as yield, moisture content, encapsulation percentage, morphology of solid particles, and particle size. Results highlighted that the most appropriate drying method for industrial purposes was spray-drying, particularly for oil-containing microcapsule formulations.     

Experimental Study and Modelling of Viscosity of Chromium Containing Slags

Viscosities of slags containing Al₂O₃, CaO, CrO_x, MgO and SiO₂ were measured in contact with metallic chromium using the rotating cylinder method. The modified Urbain model, developed at the University of Queensland, was extended to include MgO, CrO and Cr₂O₃, in addition to existing Al₂O₃, CaO, FeO and SiO₂. Chromium oxides, in general, decrease the slag viscosity, although addition of trivalent oxide raises up the liquidus temperature and thus limits the measuring range. The model was able to describe the viscosity of complex slags reasonably well in most experimental cases.     

Proactive management of distributed organisational computing: Prevention always pays, doesn't it?

Organisations have eagerly adopted the new opportunities provided by distributed computing technology. These opportunities have also created new dependency on the technology and threats of technical problems. Information technology (IT) management has to choose its position towards these new technical risks. Should the problems be prevented proactively in advance or settled reactively afterwards? This paper draws conclusions from an action research case study aimed at proactive versus reactive end-user support. Between 1994 and 1997 one of the business units in Nokia Telecommunications required a new approach for its distributed information systems (IS) to facilitate rapid organisational growth. The distributed IS and its end-user support were established and organised during a 30-month re-engineering process. These results provide a new view to the dependencies between business processes and IT. The new distributed IT has become, often insidiously, a necessity for vital business processes. Therefore, risk management should be adopted as a standard tool for IS management to identify such dependencies. Proactive actions should be aimed at those areas where IT-related business risks are identified. Proactivity should be supplemented by reactive support to provide daily assistance for the end-users.     

Variability in mechanical exposure within and between individuals performing a highly constrained industrial work task

Data on exposure variability is an important remedy for designing and interpreting studies of occupational ergonomics. The present study aimed at retrieving the within- and between-subjects variance of several mechanical exposure parameters in a repeated, short-cycle task. Seven experienced operators repeatedly secured joints using two types of hand-held nutrunners. The joints were placed in three different locations on a rack, simulating automotive assembly. Bilateral muscle activity from the upper trapezius and the lower arm extensors, as well as head and upper arm inclination was continuously monitored. Exposure levels and their variance components were assessed in several data subsets using ANOVA. The results were interpreted in terms of statistical precision and power, and discussed as markers of important ergonomic qualities. A substantial exposure variability was found within and between subjects in all joint locations and for both tools. For mixed work across tools and locations, the necessary number of subjects to arrive at a group mean exposure with 95% confidence limits corresponding to +/- 10% of the mean ranged between 8 and 158, with posture recordings tending to require smaller populations than muscle activity recordings. Within-subject variance increased 2- to 37-fold, depending on exposure parameter, when work was 'enlarged' from securings with a specified location and tool to a mix of all locations and tools. Systematic differences between subjects in variability and responsiveness to 'work enlargement' indicated individualized motor control strategies. The results illustrate the importance of exposure variability data to the design of proper measurement strategies. They also suggest that the sizes of exposure variability per se can be interpreted as operational indices of what is thought to be important ergonomic risk indicators, such as the 'sameness' of repeated operations and the allowance for flexible working techniques.     

Eye movement assessment of selective attentional capture by emotional pictures.

The eye-tracking method was used to assess attentional orienting to and engagement on emotional visual scenes. In Experiment 1, unpleasant, neutral, or pleasant target pictures were presented simultaneously with neutral control pictures in peripheral vision under instruction to compare pleasantness of the pictures. The probability of first fixating an emotional picture, and the frequency of subsequent fixations, were greater than those for neutral pictures. In Experiment 2, participants were instructed to avoid looking at the emotional pictures, but these were still more likely to be fixated first and gazed longer during the first-pass viewing than neutral pictures. Low-level visual features cannot explain the results. It is concluded that overt visual attention is captured by both unpleasant and pleasant emotional content. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Foliar Phenolics are Differently Associated with Epirrita autumnata Growth and Immunocompetence

The quality of available food may affect insect herbivores directly (via growth and survivorship) and/or indirectly (by modifying insect vulnerability to parasitoids and pathogens). We examined the relationship between different phenolic compounds, belonging to various phenolic groups, in Betula pubescens spp. czerepanovii (mountain birch) foliage and the larval performance of the geometrid Epirrita autumnata (autumnal moth). Direct effects on insect performance were described by pupal weight, developmental rate, and survivorship; indirect effects were described by the encapsulation rate of an implant inserted into the insect hemocoel, a commonly used way to describe insect immune defense. We found profound differences in the effects of different phenolic categories: several individual hydrolyzable tannins were associated positively with larval performance but negatively with level of immune defense, whereas flavonoid glycosides were inversely related to larval survival but showed no association with the larvae immune defense.     

Emotional scene content drives the saccade generation system reflexively.

The authors assessed whether parafoveal perception of emotional content influences saccade programming. In Experiment 1, paired emotional and neutral scenes were presented to parafoveal vision. Participants performed voluntary saccades toward either of the scenes according to an imperative signal (color cue). Saccadic reaction times were faster when the cue pointed toward the emotional picture rather than toward the neutral picture. Experiment 2 replicated these findings with a reflexive saccade task, in which abrupt luminosity changes were used as exogenous saccade cues. In Experiment 3, participants performed vertical reflexive saccades that were orthogonal to the emotional–neutral picture locations. Saccade endpoints and trajectories deviated away from the visual field in which the emotional scenes were presented. Experiment 4 showed that computationally modeled visual saliency does not vary as a function of scene content and that inversion abolishes the rapid orienting toward the emotional scenes. Visual confounds cannot thus explain the results. The authors conclude that early saccade target selection and execution processes are automatically influenced by emotional picture content. This reveals processing of meaningful scene content prior to overt attention to the stimulus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Harmful algae and their potential impacts on desalination operations off southern California

Seawater desalination by reverse osmosis (RO) is a reliable method for augmenting drinking water supplies. In recent years, the number and size of these water projects have increased dramatically. As freshwater resources become limited due to global climate change, rising demand, and exhausted local water supplies, seawater desalination will play an important role in the world's future water supply, reaching far beyond its deep roots in the Middle East. Emerging contaminants have been widely discussed with respect to wastewater and freshwater sources, but also must be considered for seawater desalination facilities to ensure the long-term safety and suitability of this emerging water supply. Harmful algal blooms, frequently referred to as ‘red tides’ due to their vibrant colors, are a concern for desalination plants due to the high biomass of microalgae present in ocean waters during these events, and a variety of substances that some of these algae produce. These compounds range from noxious substances to powerful neurotoxins that constitute significant public health risks if they are not effectively and completely removed by the RO membranes. Algal blooms can cause significant operational issues that result in increased chemical consumption, increased membrane fouling rates, and in extreme cases, a plant to be taken off-line. Early algal bloom detection by desalination facilities is essential so that operational adjustments can be made to ensure that production capacity remains unaffected. This review identifies the toxic substances, their known producers, and our present state of knowledge regarding the causes of toxic episodes, with a special focus on the Southern California Bight.     

Grating-cavity continuous-wave optical parametric oscillators for high-resolution mid-infrared spectroscopy

The use of grating as a spectral filter provides a simple way of improving wavelength tuning and stability of continuous-wave optical parametric oscillators (cw OPOs). In this paper, we discuss how to design and use such grating-cavity cw OPOs for high-resolution spectroscopy in the molecular fingerprint region at ～3μm. The first design presented in the paper is based on a metal-coated diffraction grating, which produces fast and broad wavelength tuning and high wavelength stability. The second design uses a bulk Bragg grating for high optical power and good spectral purity. We report a new Bragg-grating OPO and demonstrate its use in a Doppler-free absorption spectroscopy of CH4 at ～3.22μm. In addition, we describe a new balanced detection scheme, which can be used to improve the signal-to-noise ratio of absorption measurements if the measurement noise is limited by the intensity noise of the mid-infrared OPO.