6,147 research outputs found

    Fostering innovation through cultural change

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    Purpose: The paper aims to demonstrate a range of approaches to promoting innovative thought and action which can be applied in a variety of organisational contexts. Design/methodology/approach: The paper describes strategies adopted by one large academic library which sought to increase employee engagement and levels of innovation. Included is the background situation, a description of cultural change activities undertaken, information on provision of a suite of practical innovation process tools, and reference to relevant literature. Findings: The leadership framework of RMIT University, and associated developmental opportunities, benefit the library which also offers a tailored developmental programme for its leadership group. Specific purpose groups are used in the library to build capacity and promote cultural change. The library promotes involvement in professional associations and supports innovation through the provision of practical tools and techniques which can be used by staff at all levels. Building an innovative culture is challenging in a large organisation, but sustaining effort over time, utilising a variety of approaches and developing positive sub-cultures among motivated staff have been found to be beneficial. Originality/value: By describing strategies to promote an innovative organisational culture, the paper has originality. Most related library literature addresses specific innovations

    Haze in the Klang Valley of Malaysia

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    Continuous measurements of dry aerosol light scattering (Bsp) were made at two sites in the Klang Valley of Malaysia between December 1998 and December 2000. In addition 24-h PM2.5 samples were collected on a one-day-in-six cycle and the chemical composition of the aerosol was determined. Periods of excessive haze were defined as 24-h average Bsp values greater than 150 Mm-1 and these occurred on a number of occasions, between May and September 1999, during May 2000, and between July and September 2000. The evidence for smoke being a significant contributor to aerosol during periods of excessive haze is discussed and includes features of the aerosol chemistry, the diurnal cycle of Bsp, and the coincidence of forest fires on Sumatra during the southwest (SW) monsoon period, as well as transport modelling for one week of the southwest Monsoon of 2000. The study highlights that whilst transboundary smoke is a major contributor to poor visibility in the Klang Valley, smoke from fires on Peninsular Malaysia is also a contributor, and at all times, the domestic source of secondary particle production is present

    Evidence for internal electric fields in two variant ordered GaInP obtained by scanning capacitance microscopy

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    Journal ArticleSingle and two variant ordered GaInP samples are studied in cross section with the scanning capacitance microscope. Our study shows significant differences in the electronic properties of single and two variant GaInP. In unintentionally doped, ordered two variant samples, both n and p-type like domains are observed with the scanning capacitance microscope. In contrast, a spatially uniform capacitance signal is observed in unintentionally doped single variant ordered GaInP. These microscopic capacitance observations can be qualitatively explained by bend bending or internal electric fields

    Evidence of internal electric fields in GaInP2 by scanning capacitance and near-field scanning optical microscopy

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    Journal ArticleGaInP2 is studied in cross section with the scanning capacitance and near-field scanning optical microscope. Our study shows significant differences in the electronic and optical properties between ordered single- and two-variant GaInP2. In single-variant samples, spatially uniform capacitance signal, photoluminescence intensity, and band gap are observed. In contrast, a spatially nonuniform capacitance signal, photoluminescence intensity, and band gap are observed in samples with nominally uniform doping

    Shear force microscopy with capacitance detection for near-field scanning optical microscopy

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    Journal ArticleShear force microscopy is very useful for distance regulation in near-field scanning optical microscopy (NSOM). However, the optical method used to detect the shear force can cause problems when imaging photosensitive materials, i.e., the shear force detection beam can optically pump the sample. We present here a new approach to shear force detection based upon capacitance sensing. The design, operation, and performance of the capacitance detection are presented. Shear force topographic images of hard and soft surfaces are shown using tungsten and NSOM fiber tips. The closed loop vertical sensitivity achieved is 0.01 nm//Hz

    Measurement of Resonant Frequency and Quality Factor of Microwave Resonators: Comparison of Methods

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    Precise microwave measurements of sample conductivity, dielectric, and magnetic properties are routinely performed with cavity perturbation measurements. These methods require the accurate determination of quality factor and resonant frequency of microwave resonators. Seven different methods to determine the resonant frequency and quality factor from complex transmission coefficient data are discussed and compared to find which is most accurate and precise when tested using identical data. We find that the nonlinear least-squares fit to the phase vs. frequency is the most accurate and precise when the signal-to-noise ratio is greater than 65. For noisier data, the nonlinear least squares fit to a Lorentzian curve is more accurate and precise. The results are general and can be applied to the analysis of many kinds of resonant phenomena.Comment: 29 pages, 11 figure

    Feasibility of manufacturing a patient-specific spinal implant

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    Spinal fusion is performed for degenerative spinal condition when conservative measures fail. Implant size and shape are not standardised between manufacturers, and best match often means compromises. Bioprinting offers a unique opportunity to create a tailor-made solution. PURPOSE: The goal of this study was to design and manufacture a 3D-printed lumbar cage for lumbar interbody fusion

    Computational models for characterisation and design of patient-specific spinal implant

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    BACKGROUND CONTEXT: Spinal fusion is designed to reduce movements between vertebrae and therefore pain. The most used devices for this procedure are mainly made of titanium or polyether ether ketone (PEEK). However, the mismatch between devices, with standard shapes and materials, and the surrounding bones can lead to suboptimal outcomes. Computational models, namely, Finite Element Analyses (FEA), can be employed to optimise existing device and design more effective solutions. PURPOSE: The goal of this study was to compare the performance of different materials and material densities for spinal cages, and to design a novel geometry which can ideally match the anatomical characteristics of a patient. STUDY DESIGN/SETTING: Computational. PATIENT SAMPLE: Nil. OUTCOME MEASURES: Nil. METHODS: FEA were set up to simulate compression (400 N) and bending (7.5 Nm) on a generic cage design. Three materials were modelled: titanium, PEEK and polycarbonate. Polycarbonate was included as widely available within additive manufacturing techniques. For each of the cages, four designs were modelled with varying material filling density. Furthermore, a new cage was modelled to match the pre-operative computed tomography (CT) of a patient exactly. The patient-specific cage was also tested by means of FEA. RESULTS: Stress distribution was compared between all the three materials tested. Consistently, stresses increased with reducing material density. Stress peak values were lower than the respective risk of failure in all the simulated cases, confirming the feasibility of polycarbonate implants. The patient-specific design showed even stress distribution consistently within anatomical constraints. CONCLUSIONS: Computational analyses suggested the feasibility of a lighter, cheaper and patient-specific cage for spinal fusion

    Design and fabrication of 3D-printed anatomically shaped lumbar cage for intervertebra disc (IVD) degeneration treatment

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    Spinal fusion is the gold standard surgical procedure for degenerative spinal conditions when conservative therapies have been unsuccessful in rehabilitation of patients. Novel strategies are required to improve biocompatibility and osseointegration of traditionally used materials for lumbar cages. Furthermore, new design and technologies are needed to bridge the gap due to the shortage of optimal implant sizes to fill the intervertebral disc defect. Within this context, additive manufacturing technology presents an excellent opportunity to fabricate ergonomic shape medical implants. The goal of this study is to design and manufacture a 3D-printed lumbar cage for lumbar interbody fusion. Optimisations of the proposed implant design and its printing parameters were achieved via in silico analysis. The final construct was characterised via scanning electron microscopy, contact angle, x-ray micro computed tomography (μCT), atomic force microscopy, and compressive test. Preliminary in vitro cell culture tests such as morphological assessment and metabolic activities were performed to access biocompatibility of 3D-printed constructs. Results of in silico analysis provided a useful platform to test preliminary cage design and to find an optimal value of filling density for 3D printing process. Surface characterisation confirmed a uniform coating of nHAp with nanoscale topography. Mechanical evaluation showed mechanical properties of final cage design similar to that of trabecular bone. Preliminary cell culture results showed promising results in terms of cell growth and activity confirming biocompatibility of constructs. Thus for the first time, design optimisation based on computational and experimental analysis combined with the 3D-printing technique for intervertebral fusion cage has been reported in a single study. 3D-printing is a promising technique for medical applications and this study paves the way for future development of customised implants in spinal surgical applications

    Modulation of Natural Killer Cell Cytotoxicity in Human Cytomegalovirus Infection: The Role of Endogenous Class I Major Histocompatibility Complex and a Viral Class I Homolog

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    Natural killer (NK) cells have been implicated in early immune responses against certain viruses, including cytomegalovirus (CMV). CMV causes downregulation of class I major histocompatibility complex (MHC) expression in infected cells; however, it has been proposed that a class I MHC homolog encoded by CMV, UL18, may act as a surrogate ligand to prevent NK cell lysis of CMV-infected cells. In this study, we examined the role of UL18 in NK cell recognition and lysis using fibroblasts infected with either wild-type or UL18 knockout CMV virus, and by using cell lines transfected with the UL18 gene. In both systems, the expression of UL18 resulted in the enhanced killing of target cells. We also show that the enhanced killing is due to both UL18-dependent and -independent mechanisms, and that the killer cell inhibitory receptors (KIRs) and CD94/NKG2A inhibitory receptors for MHC class I do not play a role in affecting susceptibility of CMV-infected fibroblasts to NK cell–mediated cytotoxicity
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