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31.
Technology is ubiquitous in our occupational, educational and leisure lives. A fear of interacting with technology can therefore have a major impact on the quality of an individual’s life. This is particularly salient within education as an inability to maximise the benefits of technology may limit academic achievement and subsequent opportunities in life. The severity of the anxiety induced by technology has lead to a plethora of research into the prevalence of ‘technophobia’. This term may have clinical relevance and has been found to be comparable in severity to more traditional phobias [Thorpe, S. J. &; Brosnan, M. (in press). Does computer anxiety reach levels which conform to DSM IV criteria for specific phobia? Computers in Human Behavior]. This paper presents two studies examining the effect of clinically-derived treatments upon levels of anxiety induced by technology. Study 1 was a 10-week selective desensitisation programme with 16 participants (eight computer anxious, eight non-anxious). Over this period computer anxiety and coping cognitions were significantly improved in the computer anxious group and become comparable to those of the matched non-anxious controls. Study 2 was a single treatment session for anxiety. Thirty individuals identified as anxious were assigned to either a one-session treatment (n = 9) or non-treatment (n = 21) group. Initially, both groups were significantly more anxious than the non-anxious control group (n = 59). Subsequent testing established that over the period of an academic year the reduction in anxiety was three times greater in the treated group than the non-treated group such that by the end of the year the treated group no longer differed from the control group, whereas the non-treated group remained significantly more anxious. The implications and limitations of the studies are discussed.  相似文献   
32.
The rates of degradation of common chemical pesticides applied to stored grains are known to be strongly dependent on grain moisture content and temperature. A finite difference mathematical model of the processes of heat and moisture transfer and pesticide decay in aerated grain is presented and its validity is supported by experimental evidence. Aeration is shown to reduce the rate of degradation of pesticides applied to stored grain, and render the rate of decay relatively insensitive to initial grain conditions. In the temperate and sub-tropical wheat growing regions of Australia, aeration can reduce usage of the pesticide methacrifos (0-2-methoxy carbonylprop-1-enyl 0,0-dimethyl phosphorothioate) by factors of 7 and 4 respectively. The effects of initial grain moisture content, initial grain temperature, fan operation, air flow rates and geographic location are modelled. Aeration of pesticide treated grain may reduce uncertainty within the grain handling industry, thus enabling more efficient planning and resource utilization.  相似文献   
33.
Pixton and Griffiths (1971) describe the diffusion of moisture through bulk grain by means of a diffusion coefficient which is an empirically determined function of grain moisture content and temperature. This paper presents a general analysis of the diffusion mechanism based on the interstitial partial pressure of water vapour derived from hygrothermal data as the driving force, and the properties of porous beds of granular materials are invoked to calculate the resistance to diffusion. An obstructive coefficient, ψ, is determined to be 0.53 which compares excellently with literature values for randomly packed porous media, and is in accord with contention of van Brakel and Heertjes (1974) that the nature of the packing is not an important influence on the value of the obstructive coefficient.  相似文献   
34.
A new mathematical treatment of alarms that considers them as multi-variable interactions between process variables has provided the first-ever method to calculate values for alarm limits. This has resulted in substantial reductions in false alarms and hence in alarm annunciation rates in field trials. It has also unified alarm management, process control and product quality control into a single mathematical framework so that operations improvement and hence economic benefits are obtained at the same time as increased process safety. Additionally, an algorithm has been developed that advises what changes should be made to Manipulable process variables to clear an alarm. The multi-variable Best Operating Zone at the heart of the method is derived from existing historical data using equation-free methods. It does not require a first-principles process model or an expensive series of process identification experiments. Integral with the method is a new format Process Operator Display that uses only existing variables to fully describe the multi-variable operating space. This combination of features makes it an affordable and maintainable solution for small plants and single items of equipment as well as for the largest plants. In many cases, it also provides the justification for the investments about to be made or already made in process historian systems. Field Trials have been and are being conducted at IneosChlor and Mallinckrodt Chemicals, both in the UK, of the new geometric process control (GPC) method for improving the quality of both process operations and product by providing Process Alarms and Alerts of much high quality than ever before. The paper describes the methods used, including a simple visual method for Alarm Rationalisation that quickly delivers large sets of Consistent Alarm Limits, and the extension to full Alert Management with highlights from the Field Trials to indicate the overall effectiveness of the method in practice.  相似文献   
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We propose a method of using a relatively low degree of freedom (DOF) warping to accurately measure the interval change of lesions having homogeneous contrast. The setting presented here presupposes the use of interval computed tomography (CT) liver exams. After a 3 x 24 DOF warping of the later examination to match the liver's pose in the earlier exam of the interval pair is performed, the lesion's volume change is estimated using the computed difference volume of the two data sets via a novel method that counts partial volume contributions and is insensitive to slight misregistration. A mathematically generated phantom is used to quantify accuracy in the presence of noise. We also quantify the accuracy of our CT liver registrations using microcoils implanted for chemotherapy. A probabilistic liver atlas is used to support automatic masking and liver-focused registration.  相似文献   
37.
Global warming and thermohaline circulation stability   总被引:2,自引:0,他引:2  
The Atlantic thermohaline circulation (THC) plays an important role in global climate. Theoretical and palaeoclimatic evidence points to the possibility of rapid changes in the strength of the THC, including a possible quasi-permanent shutdown. The climatic impacts of such a shutdown would be severe, including a cooling throughout the Northern Hemisphere, which in some regions is greater in magnitude than the changes expected from global warming in the next 50 years. Other climatic impacts would likely include a severe alteration of rainfall patterns in the tropics, the Indian subcontinent and Europe. Modelling the future behaviour of the THC focuses on two key questions. (i) Is a gradual weakening of the THC likely in response to global warming, and if so by how much? (ii) Are there thresholds beyond which rapid or irreversible changes in the THC are likely? Most projections of the response of the THC to increasing concentrations of greenhouse gases suggest a gradual weakening over the twenty-first century. However, there is a wide variation between different models over the size of the weakening. Rapid or irreversible THC shutdown is considered a low-probability (but high-impact) outcome; however, some climate models of intermediate complexity do show the possibility of such events. The question of the future of the THC is beset with conceptual, modelling and observational uncertainties, but some current and planned projects show promise to make substantial progress in tackling these uncertainties in future.  相似文献   
38.
We have developed a new technique for quantifying methionine sulfoxide (MetSO) in protein to assess levels of oxidative stress in physiological systems. In this procedure, samples are hydrolyzed with methanesulfonic acid (MSA) in order to avoid the conversion of MetSO to methionine (Met) that occurs during hydrolysis of protein in HCl. The hydrolysate is fractionated on a cation exchange column to remove the nonvolatile MSA from amino acids, and the amino acids are then derivatized as their trimethylsilyl esters for analysis by selected ion monitoring-gas chromatography/mass spectrometry. The limit of detection of the assay is 200 pmol of MetSO per analysis, and the interassay coefficient of variation is 5.8%. Compared to current methods, the SIM-GC/MS assay avoids the potential for conversion of Met to MetSO during sample preparation, requires less sample preparation time, has lower variability, and uses mass spectrometry for sensitive and specific analyte detection.  相似文献   
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Extended previous research on perceptual grouping in infancy (Thorpe, Trehub, Morrongiello, & Bull, 1988). Infants' detection of temporal increments to silent intervals between groups of tones was compared with their detection of comparable silent increments within groups of tones. Ss were presented with standard 6-tone sequences, with the first 3 tones differing from the last 3 in harmonic structure, frequency, or intensity, and contrasting sequences with increments of 80 or 100 ms to the silent interval between the 3rd and 4th tone (XXX OOO, between groups) or between the 4th and 5th tone (XXXO OO, within group). Infants discriminated temporally altered sequences from the standard only when the increments occurred within a group. The authors conclude that perceptual grouping processes are operative in infancy and that infants perceive the silent increments between groups of sounds as longer than identical intervals within a group, as do adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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