55 resultados para conditions of contact


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To characterize and discover the determinants of the frequency of wear (FOW) of contact lenses. Survey forms were sent to contact lens fitters in up to 40 countries between January and March every year for 5 consecutive years (2007–2011). Practitioners were asked to record data relating to the first 10 contact lens fits or refits performed after receiving the survey form. Only data for daily wear lens fits were analyzed. Data were collected in relation to 74,510 and 9,014 soft and rigid lens fits, respectively. Overall, FOW was 5.9±1.7 days per week (DPW). When considering the proportion of lenses worn between one to seven DPW, the distribution for rigid lenses is skewed toward full-time wear (7 DPW), whereas the distribution for soft daily disposable lenses is perhaps bimodal, with large and small peaks at seven and two DPW, respectively. There is a significant variation in FOW among nations (P<0.0001), ranging from 6.8±1.0 DPW in Greece to 5.1±2.5 DPW in Kuwait. For soft lenses, FOW increases with decreasing age. Females (6.0±1.6 DPW) wear lenses more frequently than males (5.8±1.7 DPW) (P=0.0002). FOW is greater among those wearing presbyopic corrections (6.1±1.4 DPW) compared with spherical (5.9±1.7 DPW) and toric (5.9±1.6 DPW) designs (P<0.0001). FOW with hydrogel peroxide systems (6.4±1.1 DPW) was greater than that with multipurpose systems (6.2±1.3 DPW) (P<0.0001).

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In this paper, the author discusses the reform agenda undertaken by UniversitiSains Malaysia (USM) to contextualise higher education reform within culturaland social theory. It is important to understand leadership in leading reformwithin a broader and more holistic fashion that takes into account localculture, politics and history. University Sains Malaysia is embarking on what isreferred to as the APEX agenda. The APEX strategy in Malaysia is an importantapproach towards achieving world-class status university institutions. The ApexUniversities will be the nation’s centres of academic distinction. Ensuring andbuilding upon the ethical authority that APEX gives USM, the challenge of leadership in USM is to engage in the forces of globalization and modernizationwhile at the same time take cognizance of the characteristics and demands ofMalaysian culture as central still to the successful mission of USM.

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The early development of Australian life insurance was marked by the failure of stock companies to successfully establish a market presence. Mutual insurers emerged in the mid-nineteenth century in response to this gap in supply. The underlying rationale behind their establishment differed but the business model adopted proved remarkably successful. Mutual life insurers dominated the market for life insurance for nearly a century. This chapter investigates mutualism as a business strategy that addressed particular problems associated with doing business in a small and underdeveloped economy. Business and social networks were important facilitators of new business. In addition, most mutual life insurers had a social/philanthropic charter and they were able to utilize this to build business. An outcome of this mix was the emergence of a particular type of entrepreneurship that fostered innovative product development and cemented the role of mutual insurers as market leaders.. The Variety, Choice, Governance, and Regulation of Organizational Forms 2.

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The peg-in-hole insertion and adjustment operation is one of the most common tasks in the robotic and automatic assembly processes. Fine motion strategies associated with adjustment operations on a peg-in-hole are fundamental manipulations that can be utilised in dynamic assembly and reconfigurable workholding or fixturing systems. This paper presents a comprehensive study of robotic-based height adjustment of a cylindrical pair based on maintaining minimum contact forces between the links. The outer link is held by the end-effector of a six-DOF (Degrees of freedom) serial articulated robot manipulator. The environment represented by the inner link can be either static or dynamic. A force-based approach and a d value approach are established to determine the type of contact that exists between the links of a cylindrical pair, and to extract control parameters. Based on the comparison and analysis of these two approaches, a hybrid methodology is established by combining a d value approach with a force-based approach for contact state determination. Formulations capable of extracting necessary control parameters, which ensure minimum contact forces between the links, are established from both planar and spatial viewpoints under both static and dynamic environmental conditions. Experimental results demonstrate the effectiveness of the proposed methodology.

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 This paper further the investigation of Doppler radar feasibility in measuring the flow in and out due to inhalation and exhalation under different conditions of breathing activities. Three different experiment conditions were designed to investigate the feasibility and consistency of Doppler radar which includes the combination of the states of normal breathing, deep breathing and apnoea state were demonstrated. The obtained Doppler radar signals were correlated and compared with the gold standard medical device, spirometer, yielding a good correlations between both devices. We also demonstrated the calibration of the Doppler radar signal can be performed in a simple manner in order to have a good agreements with the spirometer readings. The measurement of the flow in and out during the breathing activities can be measured accurately under different dynamics of breathing as long as the calibration is performed correctly.

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Friction is a critical factor for sheet metal forming (SMF). The Coulomb friction model is usually used in most finite element (FE) simulation for SMF. However, friction is a function of the local contact deformation conditions, such as local pressure, roughness and relative velocity. Frictional behaviour between contact surfaces can be based on three cases: boundary, hydrodynamic and mixed lubrication. In our microscopic friction model based on the finite element method (FEM), the case of dry contact between sheet and tool has been considered. In the view of microscopic geometry, roughness depends upon amplitude and wavelength of surface asperities of sheet and tool. The mean pressure applied on the surface differs from the pressure over the actual contact area. The effect of roughness (microscopic geometric condition) and relative speed of contact surfaces on friction coefficient was examined in the FE model for the microscopic friction behaviour. The analysis was performed using an explicit FE formulation. In this study, it was found that the roughness of deformable sheet decreases during sliding and the coefficient of friction increases with increasing roughness of contact surfaces. Also, the coefficient of friction increases with the increase of relative velocity and adhesive friction coefficient between contact surfaces.

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This paper investigates the extent to which the technical and social contexts of organizations independently affect levels of workplace trust. We argue that, in an organizational context, trust is not just a relationship between an individual subject (the truster) and an object (the trustee) but is subject to effects from the conditions of the work relationship itself. We describe the organizational context as comprising both a technical system of production (where work gets done through the specification of tasks) and a social system of work (where problems of effort, compliance, conformity and motivation are managed). We analyse the relationship between trust and these two aspects of workplace context (technical and social systems). We also operationalize this in terms of differences between industries,  occupational composition and human resource management practices. The model is tested using data drawn from the 1995 Australian Workplace Industrial Relations Survey. The results confirm that differences in industry, occupational composition and HRM practices all impact on levels of workplace trust. We review these results in terms of their implications for future research into the problem of analysing variation in trust at both the workplace and individual levels.

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Nanofretting refers to cyclic movements of contact interfaces with the relative displacement amplitude at the nanometer scale, where the contact area and normal load are usually much smaller than those in fretting. Nanofretting widely exists in microelctromechanical systems (MEMS) and may become a key tribological concern besides microwear and adhesion. With a triboindenter, the nanofretting behaviors of a nickel titanium (NiTi) shape memory alloy are studied under various normal loads (1–10 mN) and tangential displacement amplitudes (2–500 nm) by using a spherical diamond tip. Similar to fretting, the nanofretting of NiTi/diamond pair can also be divided into different regimes upon various shapes of tangential force–displacement curves. The dependence of nanofretting regime on the normal load and the displacement amplitude can be summarized in a running condition nanofretting map. However, due to the surface and size effects, nanofretting operates at some different conditions, such as improved mechanical properties of materials at the nanometer scale, small apparent contact area and single-asperity contact behavior. Consequently, different from fretting, nanofretting was found to exhibit several unique behaviors: (i) the maximum tangential force in one cycle is almost unchanged during a nanofretting test, which is different from a fretting test where the maximum tangential force increases rapidly in the first dozens of cycles; (ii) the tangential stiffness in nanofretting is three orders magnitude smaller than that in fretting; (iii) the friction coefficient in nanofretting is much lower than that in fretting in slip regime; (iv) no obvious damage was observed after 50 cycles of nanofretting under a normal load of 10 mN.

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This article explores some aspects of the role of race and gender in shaping women postgraduate students' experience of intercultural study. It focuses on various social and cultural aspects of their sojourn. These were suggested by data from two small pilot research projects investigating the experiences of two cohorts of international women postgraduate students, the one studying in an Australian university and the other, a Canadian. The authors focus particularly on the intersections between the students' representation of themselves as women and the way they see themselves represented by their host cultures. In other words, they are interested in the students' understandings of themselves as 'other', and how this impacts on their representations of 'self'. The authors suggest that these representations reflect a process of negotiation of identity that occurs in what they call the globalising university 'contact zone'. The concept of contact zones derives from post-colonial theory. A further goal of this article, then, is to examine how such data appear when viewed from a post-colonial perspective.