945 resultados para Few
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To date, research on P-O fit has focused heavily on the effect of P-O fit on individual and organisational outcomes. Few studies have attempted to explain how or why P-O fit leads to these outcomes. Meglino, Ravlin, and Adkins (1989) and Schein (1985) identified several intervening mechanisms for explaining fit-outcome relationships but only few of these explanations have been tested empirically (Cable & Edwards, 2004; Edwards & Cable, 2009; Kalliath, Bluedorn, & Strube, 1999). This thesis investigates role conflict, cognitive style and organisational justice as three potential mediating mechanisms in the relationship between P-O fit (defined as fit between personal and organisational values – value congruence or value fit) and outcomes including job satisfaction, job performance, service performance, affective commitment and continuance commitment. The study operationalised P-O fit using three measures: subjective fit, perceived fit and objective fit. The mediation model of subjective fit was tested using a Mplus analytical technique, while the mediation models of both perceived and objective fit were tested by modeling the difference between two scores (that is, between personal values and organisational values) using a polynomial regression and response surface analysis (Edwards, 1993). A survey of 558 mid-level managers from seven Brunei public sector organisations provided the data. Our results showed that the relationship between P-O fit and outcomes was partially mediated by organisational justice and cognitive style - for all the three measures of fit, while role conflict had no mediating effects. The findings from this research therefore have both theoretical and practical implications. This research contributes to the literature by combining these theoretical explanations for value congruence effects into one integrated model, and by providing evidence on the partial mediating effects of organisational justice and cognitive style. Future research needs to address and investigate other potential mechanisms by which value congruence affects individual and organisational outcomes. In addition, the study is considered to be the first to test these mediating roles for a value fit-outcomes relationship using three different measures of fit in a non-Western context.
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This paper presents a key based generic model for digital image watermarking. The model aims at addressing an identified gap in the literature by providing a basis for assessing different watermarking requirements in various digital image applications. We start with a formulation of a basic watermarking system, and define system inputs and outputs. We then proceed to incorporate the use of keys in the design of various system components. Using the model, we also define a few fundamental design and evaluation parameters. To demonstrate the significance of the proposed model, we provide an example of how it can be applied to formally define common attacks.
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Some minerals are colloidal and show no X-ray diffraction patterns. Vibrational spectroscopy offers one of the few methods for the assessment of the structure of these types of mineral. Among this group of minerals is pitticite simply described as Fe, AsO4, SO4, H2O. The objective of this research is to determine the molecular structure of the mineral pitticite using vibrational spectroscopy. Raman microscopy offers a useful method for the analysis of such colloidal minerals. Raman and infrared bands are attributed to the , and water stretching vibrations. The Raman spectrum is dominated by a very intense sharp band at 983 cm−1 assigned to the symmetric stretching mode. A strong Raman band at 1041 cm−1 is observed and is assigned to the antisymmetric stretching mode. Low intensity Raman bands at 757 and 808 cm−1 may be assigned to the antisymmetric and symmetric stretching modes. Raman bands observed at 432 and 465 cm−1 are attributable to the doubly degenerate ν2(SO4)2- bending mode.
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The availability and use of online counseling approaches has increased rapidly over the last decade. While research has suggested a range of potential affordances and limitations of online counseling modalities, very few studies have offered detailed examinations of how counselors and clients manage asynchronous email counseling exchanges. In this paper we examine email exchanges involving clients and counselors through Kids Helpline, a national Australian counseling service that offers free online, email and telephone counseling for young people up to the age of 25. We employ tools from the traditions of ethnomethodology and conversation analysis to analyze the ways in which counselors from Kids Helpline request that their clients call them, and hence change the modality of their counseling relationship, from email to telephone counseling. This paper shows the counselors’ three multi-layered approaches in these emails as they negotiate the potentially delicate task of requesting and persuading a client to change the trajectory of their counseling relationship from text to talk without placing that relationship in jeopardy.
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In Australia, there is only one, newly established, dedicated mental health service catering specifically for the signing *Deaf community. It is staffed by four part-time hearing professionals and based in Brisbane. There are currently no Deaf psychologists or psychiatrists and there is no valid or reliable empirical evidence on outcomes for Deaf people accessing specialised or mainstream mental health services. Further compounding these issues, is the fact that there are no sign language versions of the most common standardised mental health or psychological instruments available to clinicians in Australia. Contemporary counselling literature is acknowledging the role of the therapeutic alliance and the impact of 'common factors' on therapeutic outcomes. However, these issues are complicated by the relationship between the Deaf client and the hearing therapist being a cross-cultural exchange. The disability model of deafness is contentious and few professionals in Australia have the requisite knowledge and understanding of deafness from a cultural perspective to attend to the therapeutic relationship with this in mind. Consequently, Deaf people are severely disadvantaged by the current lack of services, resources and skilled professionals in the field of deafness and psychology in this country. The primary aim of the following program of research has been to propose a model for culturally affirmative service delivery and to provide clinicians with tools to evaluate the effect of their therapeutic work with Deaf people seeking mental health treatment. The research document is presented as a thesis by publication and comprises four specific objectives formulated in response to the lack of existing services and resources. The first objective was to explore the use of social constructionist counselling techniques and a reflecting team with Deaf clients, hearing therapists and an interpreter. Following the establishment of a pilot counselling clinic, indepth semi-structured interviews were conducted with two long-term clients following the one year pilot of this service. These interviews generated recommendations for the development of a new 'enriched' model of counselling to be implemented and evaluated in later stages of the research program. The second objective was to identify appropriate psychometric measures that could be translated into Australian Sign Language (Auslan) for research into efficacy, effectiveness and counselling outcomes. Two instruments were identified as potentially suitable; the Outcome Rating Scale (ORS), a measure of global functioning, and the Session Rating Scale (SRS), a measure of therapeutic alliance. A specialised team of bi-lingual and bi-cultural interpreters, native signers and the primary researcher for this thesis, produced the ORS-Auslan and the SRS-Auslan in DVD format, using the translation and back-translation process. The third objective was to establish the validity and reliability of these new Auslan measures based on normative data from the Deaf community. Data from the ORS-Auslan was collected from one clinical and one non-clinical sample of Deaf people. Statistical analyses revealed that the ORS-Auslan is reliable, valid and adequately distinguishes between clinical and non-clinical presentations. Furthermore, construct validity has been established using a yet to be validated sign language version of the Depression, Anxiety and Stress Scale-21 items (DASS-21), providing a platform for further research using the DASS-21 with Deaf people. The fourth objective was to evaluate counselling outcomes following the implementation of an enriched counselling service, based on the findings generated by the first objective, and using the newly translated Auslan measures. A second university counselling clinic was established and implemented over the course of one year. Practice-based evidence guided the research and the ORS-Auslan and the SRS-Auslan were administered at every session and provided outcome data on Deaf clients' global functioning. Data from six clients over the course of ten months indicated that this culturally affirmative model was an effective approach for these six clients. This is the first time that outcome data have been collected in Australia using valid and reliable Auslan measures to establish preliminary evidence for the effectiveness of any therapeutic intervention for clinical work with adult, signing Deaf clients. The research generated by this thesis contributes theoretical knowledge, professional development and practical resources that can be used by a variety of mental health clinicians in the context of mental health service delivery to Deaf clients in Australia.
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The potential of distributed reactive power control to improve the voltage profile of radial distribution feeders has been reported in literature by few authors. However, the multiple inverters injecting or absorbing reactive power across a distribution feeder may introduce control interactions and/or voltage instability. Such controller interactions can be alleviated if the inverters are allowed to operate on voltage droop. First, the paper demonstrates that a linear shallow droop line can maintain the steady state voltage profile close to reference, up to a certain level of loading. Then, impacts of the shallow droop line control on line losses and line power factors are examined. Finally, a piecewise linear droop line which can achieve reduced line losses and close to unity power factor at the feeder source is proposed.
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Eccentric exercise is the conservative treatment of choice for mid-portion Achilles tendinopathy. While there is a growing body of evidence supporting the medium to long term efficacy of eccentric exercise in Achilles tendinopathy treatment, very few studies have investigated the short term response of the tendon to eccentric exercise. Moreover, the mechanisms through which tendinopathy symptom resolution occurs remain to be established. The primary purpose of this thesis was to investigate the acute adaptations of the Achilles tendon to, and the biomechanical characteristics of, the eccentric exercise protocol used for Achilles tendinopathy rehabilitation and a concentric equivalent. The research was conducted with an orientation towards exploring potential mechanisms through which eccentric exercise may bring about a resolution of tendinopathy symptoms. Specifically, the morphology of tendinopathic and normal Achilles tendons was monitored using high resolution sonography prior to and following eccentric and concentric exercise, to facilitate comparison between the treatment of choice and a similar alternative. To date, the only proposed mechanism through which eccentric exercise is thought to result in symptom resolution is the increased variability in motor output force observed during eccentric exercise. This thesis expanded upon prior work by investigating the variability in motor output force recorded during eccentric and concentric exercises, when performed at two different knee joint angles, by limbs with and without symptomatic tendinopathy. The methodological phase of the research focused on establishing the reliability of measures of tendon thickness, tendon echogenicity, electromyography (EMG) of the Triceps Surae and the standard deviation (SD) and power spectral density (PSD) of the vertical ground reaction force (VGRF). These analyses facilitated comparison between the error in the measurements and experimental differences identified as statistically significant, so that the importance and meaning of the experimental differences could be established. One potential limitation of monitoring the morphological response of the Achilles tendon to exercise loading is that the Achilles tendon is continually exposed to additional loading as participants complete the walking required to carry out their necessary daily tasks. The specific purpose of the last experiment in the methodological phase was to evaluate the effect of incidental walking activity on Achilles tendon morphology. The results of this study indicated that walking activity could decrease Achilles tendon thickness (negative diametral strain) and that the decrease in thickness was dependent on both the amount of walking completed and the proximity of walking activity to the sonographic examination. Thus, incidental walking activity was identified as a potentially confounding factor for future experiments which endeavoured to monitor changes in tendon thickness with exercise loading. In the experimental phase of this thesis the thickness of Achilles tendons was monitored prior to and following isolated eccentric and concentric exercise. The initial pilot study demonstrated that eccentric exercise resulted in a greater acute decrease in Achilles tendon thickness (greater diametral strain) compared to an equivalent concentric exercise, in participants with no history of Achilles tendon pain. This experiment was then expanded to incorporate participants with unilateral Achilles tendinopathy. The major finding of this experiment was that the acute decrease in Achilles tendon thickness observed following eccentric exercise was modified by the presence of tendinopathy, with a smaller decrease (less diametral strain) noted for tendinopathic compared to healthy control tendon. Based on in vitro evidence a decrease in tendon thickness is believed to reflect extrusion of fluid from the tendon with loading. This process would appear to be limited by the presence of pathology and is hypothesised to be a result of the changes in tendon structure associated with tendinopathy. Load induced fluid movement may be important to the maintenance of tendon homeostasis and structure as it has the potential to enhance molecular movement and stimulate tendon remodelling. On this basis eccentric exercise may be more beneficial to the tendon than concentric exercise. Finally, EMG and motor output force variability (SD and PSD of VGRF) were investigated while participants with and without tendinopathy performed the eccentric and concentric exercises. Although between condition differences were identified as statistically significant for a number of force variability parameters, the differences were not greater than the limits of agreement for repeated measures. Consequently the meaning and importance of these findings were questioned. Interestingly, the EMG amplitude of all three Triceps Surae muscles did not vary with knee joint angle during the performance of eccentric exercise. This raises questions pertaining to the functional importance of performing the eccentric exercise protocol at each of the two knee joint angles as it is currently prescribed. EMG amplitude was significantly greater during concentric compared to eccentric muscle actions. Differences in the muscle activation patterns may result in different stress distributions within the tendon and be related to the different diametral strain responses observed for eccentric and concentric muscle actions.
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The city centre represents a complex environment for cycling with large volumes of pedestrians and motorised vehicles and frequent signalised intersections. Much of the previous literature has focused on cyclist-motor vehicle interactions because of the safety implications for cyclists, but there is increasing concern from pedestrians about the threats they perceive from cyclists. In the absence of objective data, this has the potential to lead to restrictions on cyclist access and behaviour. This presentation reports the development of a method to study the extent of cycling in the city centre and the frequency and nature of interactions between cyclists and pedestrians. Queensland is one of the few Australian jurisdictions that permits adults to cycle on the footpath and this was also of interest. 1992 cyclists were observed at six locations in the Brisbane city centre, during 7-9am, 9-11am, 2-4pm and 4-6pm on four weekdays in October 2010. The majority (85.5%) of cyclists were male, and 21.8% rode on the footpath. Females were more likely to travel on the footpath than males. One or more pedestrians were within 1m for 18.1% of observed cyclists, and one or more pedestrians were within 5m for 39.1% of observed cyclists. There were few conflicts, defined as an occasion where if no one took evasive action a collision would occur, between cyclists and pedestrians or vehicles (1.1% and 0.6% respectively) but they were more common for adolescents and riders not wearing (or not fastening) helmets.
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Introduction / objectives Many strategies are used to control MRSA in hospitals. Only a few have been assessed in clinical trials and it is not obvious how findings should be generalised between settings. Uncertainty remains about which strategies represent the most appropriate use of scarce resources. We assess the cost-effectiveness of alternative MRSA screening and infection control strategies in England and Wales and discuss international relevance. Methods Models of MRSA transmission in ICUs and general medical (GM) wards were developed and used to evaluate different screening methods combined with decolonisation or isolation. Strategies were compared in terms of costs and health benefits (quality adjusted life years, QALYs). Different prevalences, proportions of high risk patients and ward sizes were investigated, and probabilistic sensitivity analyses (PSA) conducted. Results Decolonisation strategies were cost-saving in ICUs at a 5% admission prevalence, with admission and weekly PCR screening the most cost-effective (£3,929/QALY). In ICUs, screening and isolation reduced infection rates by ~10%. With admission prevalence ≤5%, targeting screening and isolation to high risk patients was optimal. In GM wards decolonisation and isolation strategies, though able to reduce MRSA infection rates up to ~50%, were not cost-effective. Conclusion The largest reductions in MRSA infection were achieved by screening and decolonisation strategies, and were cost-effective in ICU settings. In comparison, there is limited potential for screening and control strategies to be cost-effective in GM wards due to lower infection and mortality rates.
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Bicycling at night is more dangerous than in the daytime and poor conspicuity is likely to be a contributing factor. The use of reflective markings on a pedestrian’s major joints to facilitate the perception of biological motion has been shown to greatly enhance pedestrian conspicuity at night, but few corresponding data exist for bicyclists. Twelve younger and twelve older participants drove around a closed-road circuit at night and indicated when they first saw a bicyclist who wore black clothing either alone, or together with a reflective bicycling vest, or a vest plus ankle and knee reflectors. The bicyclist pedaled in place on a bicycle that had either a static or flashing light, or no light on the handlebars. Bicyclist clothing significantly affected conspicuity; drivers responded to bicyclists wearing the vest plus ankle and knee reflectors at significantly longer distances than when the bicyclist wore the vest alone or black clothing without a vest. Older drivers responded to bicyclists less often and at shorter distances than younger drivers. The presence of a bicycle light, whether static or flashing, did not enhance the conspicuity of the bicyclist; this may result in bicyclists who use a bicycle light being overconfident of their own conspicuity at night. The implications of our findings are that ankle and knee markings are a simple and very effective approach for enhancing bicyclist conspicuity at night.
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Background: Few studies have specifically investigated the functional effects of uncorrected astigmatism on measures of reading fluency. This information is important to provide evidence for the development of clinical guidelines for the correction of astigmatism. Methods: Participants included 30 visually normal, young adults (mean age 21.7 ± 3.4 years). Distance and near visual acuity and reading fluency were assessed with optimal spectacle correction (baseline) and for two levels of astigmatism, 1.00DC and 2.00DC, at two axes (90° and 180°) to induce both against-the-rule (ATR) and with-the-rule (WTR) astigmatism. Reading and eye movement fluency were assessed using standardized clinical measures including the test of Discrete Reading Rate (DRR), the Developmental Eye Movement (DEM) test and by recording eye movement patterns with the Visagraph (III) during reading for comprehension. Results: Both distance and near acuity were significantly decreased compared to baseline for all of the astigmatic lens conditions (p < 0.001). Reading speed with the DRR for N16 print size was significantly reduced for the 2.00DC ATR condition (a reduction of 10%), while for smaller text sizes reading speed was reduced by up to 24% for the 1.00DC ATR and 2.00DC condition in both axis directions (p<0.05). For the DEM, sub-test completion speeds were significantly impaired, with the 2.00DC condition affecting both vertical and horizontal times and the 1.00DC ATR condition affecting only horizontal times (p<0.05). Visagraph reading eye movements were not significantly affected by the induced astigmatism. Conclusions: Induced astigmatism impaired performance on selected tests of reading fluency, with ATR astigmatism having significantly greater effects on performance than did WTR, even for relatively small amounts of astigmatic blur of 1.00DC. These findings have implications for the minimal prescribing criteria for astigmatic refractive errors.
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There has been discussion whether corporate decision-making can be helped by decision support systems regarding qualitative aspects of decision making (e.g. trouble shooting)(Löf and Möller, 2003). Intelligent decision support systems have been developed to help business controllers to perform their business analysis. However, few papers investigated the user’s point of view regarding such systems. How do decision-makers perceive the use of decision support systems, in general, and dashboards in particular? Are dashboards useful tools for business controllers? Based on the technology acceptance model and on the positive mood theory, we suggest a series of antecedent factors that influence the perceived usefulness and perceived ease of use of dashboards. A survey is used to collect data regarding the measurement constructs. The managerial implications of this paper consist in showing the degree of penetration of dashboards in the decision making in organizations and some of the factors that explain this respective penetration rate.
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From one view of composition—let us call it the inspired or “Mozartian” view—musical compositions arrive fully formed in the mind of the composer and simply require transcription. In reality, however, it seems that very few people are so inspired, and composition is often more akin to a gradual clarification and refinement of partially formed ideas on the musical landscape. Particular landmarks in the compositional landscape tend to become clear before others, such that the incomplete piece is a patchwork of disconnected musical islands. An interactive evolutionary morphing system may provide some assistance for composers, to help build bridges between musical islands by generating hybrid musical transitions.
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Low oxygen pressure (hypoxia) plays an important role in stimulating angiogenesis; there are, however, few studies to prepare hypoxia-mimicking tissue engineering scaffolds. Mesoporous bioactive glass (MBG) has been developed as scaffolds with excellent osteogenic properties for bone regeneration. Ionic cobalt (Co) is established as a chemical inducer of hypoxia-inducible factor (HIF)-1α, which induces hypoxia-like response. The aim of this study was to develop hypoxia-mimicking MBG scaffolds by incorporating ionic Co2+ into MBG scaffolds and investigate if the addition of Co2+ ions would induce a cellular hypoxic response in such a tissue engineering scaffold system. The composition, microstructure and mesopore properties (specific surface area, nano-pore volume and nano-pore distribution) of Co-containing MBG (Co-MBG) scaffolds were characterized and the cellular effects of Co on the proliferation, differentiation, vascular endothelial growth factor (VEGF) secretion, HIF-1α expression and bone-related gene expression of human bone marrow stromal cells (BMSCs) in MBG scaffolds were systematically investigated. The results showed that low amounts of Co (< 5%) incorporated into MBG scaffolds had no significant cytotoxicity and that their incorporation significantly enhanced VEGF protein secretion, HIF-1α expression, and bone-related gene expression in BMSCs, and also that the Co-MBG scaffolds support BMSC attachment and proliferation. The scaffolds maintain a well-ordered mesopore channel structure and high specific surface area and have the capacity to efficiently deliver antibiotics drugs; in fact, the sustained released of ampicillin by Co-MBG scaffolds gives them excellent anti-bacterial properties. Our results indicate that incorporating cobalt ions into MBG scaffolds is a viable option for preparing hypoxia-mimicking tissue engineering scaffolds and significantly enhanced hypoxia function. The hypoxia-mimicking MBG scaffolds have great potential for bone tissue engineering applications by combining enhanced angiogenesis with already existing osteogenic properties.
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Due to their large surface area, complex chemical composition and high alveolar deposition rate, ultrafine particles (UFPs) (< 0.1 ìm) pose a significant risk to human health and their toxicological effects have been acknowledged by the World Health Organisation. Since people spend most of their time indoors, there is a growing concern about the UFPs present in some indoor environments. Recent studies have shown that office machines, in particular laser printers, are a significant indoor source of UFPs. The majority of printer-generated UFPs are organic carbon and it is unlikely that these particles are emitted directly from the printer or its supplies (such as paper and toner powder). Thus, it was hypothesised that these UFPs are secondary organic aerosols (SOA). Considering the widespread use of printers and human exposure to these particles, understanding the processes involved in particle formation is of critical importance. However, few studies have investigated the nature (e.g. volatility, hygroscopicity, composition, size distribution and mixing state) and formation mechanisms of these particles. In order to address this gap in scientific knowledge, a comprehensive study including state-of-art instrumental methods was conducted to characterise the real-time emissions from modern commercial laser printers, including particles, volatile organic compounds (VOCs) and ozone (O3). The morphology, elemental composition, volatility and hygroscopicity of generated particles were also examined. The large set of experimental results was analysed and interpreted to provide insight into: (1) Emissions profiles of laser printers: The results showed that UFPs dominated the number concentrations of generated particles, with a quasi unimodal size distribution observed for all tests. These particles were volatile, non-hygroscopic and mixed both externally and internally. Particle microanalysis indicated that semi-volatile organic compounds occupied the dominant fraction of these particles, with only trace quantities of particles containing Ca and Fe. Furthermore, almost all laser printers tested in this study emitted measurable concentrations of VOCs and O3. A positive correlation between submicron particles and O3 concentrations, as well as a contrasting negative correlation between submicron particles and total VOC concentrations were observed during printing for all tests. These results proved that UFPs generated from laser printers are mainly SOAs. (2) Sources and precursors of generated particles: In order to identify the possible particle sources, particle formation potentials of both the printer components (e.g. fuser roller and lubricant oil) and supplies (e.g. paper and toner powder) were investigated using furnace tests. The VOCs emitted during the experiments were sampled and identified to provide information about particle precursors. The results suggested that all of the tested materials had the potential to generate particles upon heating. Nine unsaturated VOCs were identified from the emissions produced by paper and toner, which may contribute to the formation of UFPs through oxidation reactions with ozone. (3) Factors influencing the particle emission: The factors influencing particle emissions were also investigated by comparing two popular laser printers, one showing particle emissions three orders of magnitude higher than the other. The effects of toner coverage, printing history, type of paper and toner, and working temperature of the fuser roller on particle number emissions were examined. The results showed that the temperature of the fuser roller was a key factor driving the emission of particles. Based on the results for 30 different types of laser printers, a systematic positive correlation was observed between temperature and particle number emissions for printers that used the same heating technology and had a similar structure and fuser material. It was also found that temperature fluctuations were associated with intense bursts of particles and therefore, they may have impact on the particle emissions. Furthermore, the results indicated that the type of paper and toner powder contributed to particle emissions, while no apparent relationship was observed between toner coverage and levels of submicron particles. (4) Mechanisms of SOA formation, growth and ageing: The overall hypothesis that UFPs are formed by reactions with the VOCs and O3 emitted from laser printers was examined. The results proved this hypothesis and suggested that O3 may also play a role in particle ageing. In addition, knowledge about the mixing state of generated particles was utilised to explore the detailed processes of particle formation for different printing scenarios, including warm-up, normal printing, and printing without toner. The results indicated that polymerisation may have occurred on the surface of the generated particles to produce thermoplastic polymers, which may account for the expandable characteristics of some particles. Furthermore, toner and other particle residues on the idling belt from previous print jobs were a very clear contributing factor in the formation of laser printer-emitted particles. In summary, this study not only improves scientific understanding of the nature of printer-generated particles, but also provides significant insight into the formation and ageing mechanisms of SOAs in the indoor environment. The outcomes will also be beneficial to governments, industry and individuals.