297 resultados para 13368-008
Resumo:
The kaolinite (Kaol) intercalated with potassium acetate (Ac) was prepared and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry. Molecular dynamic simulation was performed to investigate the structure of Kaol–Ac intercalation complex and the hydrogen bonds between Kaol and intercalated Ac andwater using INTERFACE forcefield. The acetate anions andwater arranged in a bilayer structure in the interlayer space of Kaol. The potassium cations distributed in the interlayer space and strongly coordinated with acetate anions aswell aswater rather than keyed into the ditrigonal holes of tetrahedral surface of Kaol. Strong hydrogen bonds formed between the hydrogen atoms of hydroxyl on the octahedral surface and oxygen atoms of both acetate anions and water. The acetate anions andwater also weakly bonded hydrogen to the silica tetrahedral surface through their hydrogen atoms with the oxygen atoms of silica tetrahedral surface.
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On the basis of the growing interest on the impact of airborne particles on human exposure as well as the strong debate in Western countries on the emissions of waste incinerators, this work reviewed existing literature to: (i) show the emission factors of ultrafine particles (particles with a diameter less than 100 nm) of waste incinerators, and; (ii) assess the contribution of waste incinerators in terms of ultrafine particles to exposure and dose of people living in the surrounding areas of the plants in order to estimate eventual risks. The review identified only a limited number of studies measuring ultrafine particle emissions, and in general they report low particle number concentrations at the stack (the median value was equal to 5.5×103 part cm-3), in most cases higher than the outdoor background value. The lowest emissions were achieved by utilization of the bag-house filter which has an overall number-based filtration efficiency higher than 99%. Referring to reference case, the corresponding emission factor is equal to 9.1×1012 part min-1, that is lower than one single high-duty vehicle. Since the higher particle number concentrations found in the most contributing microenvironments to the exposure (indoor home, transportation, urban outdoor), the contribution of the waste incinerators to the daily dose can be considered as negligible.
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The main aim of the present study was to estimate size segregated doses from e-cigarette aerosols as a function of the airway generation number in lung lobes.. After a 2-second puff, 7.7×1010 particles (DTot) with a surface area of 3.6×103 mm2 (STot), and 3.3×1010 particles with a surface area of 4.2×103 mm2 were deposited in the respiratory system for the electronic and conventional cigarettes, respectively. Alveolar and tracheobronchial deposited doses were compared to the ones received by non-smoking individuals in Western countries, showing a similar order of magnitude. Total regional doses (DR), in head and lobar tracheobronchial and alveolar regions, ranged from 2.7×109 to 1.3×1010 particles and 1.1×109 to 5.3×1010 particles, for the electronic and conventional cigarettes, respectively. DR in the right-upper lung lobe was about twice that found in left-upper lobe and 20% greater in right-lower lobe than the left-lower lobe.
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Fluctuations in transit ridership pattern over the year have always concerned transport planners, operators and researchers. Predominantly, metrological elements have been specified to explain variability in ridership volume. However, the outcome of this research points to new direction to explain ridership fluctuation in Brisbane. It explored the relationship between daily bus ridership, seasonality and weather variables for a one-year period, 2012. Rather than segregating the entire year’s ridership into the four calendar seasons (summer, autumn, spring, and winter), this analysis distributed the yearly ridership into nine complex seasonality blocks. These represent calendar season, school/university (academic) period and their corresponding holidays, as well as other observant holidays such as Christmas. The dominance of complex seasonality over typical calendar season was established through analysis and using Multiple Linear Regression (MLR). This research identified a very strong association between complex seasonality and bus ridership. Furthermore, an expectation that Brisbane’s subtropical summer is unfavourable to transit usage was not supported by the findings of this study. A nil association of precipitation and temperature was observed in this region. Finally, this research developed a ridership estimation model, capable of predicting daily ridership within very limited error range. Following the application of this developed model, the estimated annual time series data of each suburb was analysed using Fourier Transformation to appreciate whether any cyclical effects remained, compared with the original data.
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This study examines the context of coordinated responses, triggers for coordinated responses, and preference for or choice of coordinating strategies in road traffic injury prevention at a local level in some OECD countries. This aim is achieved through a mixed-methodology. In this respect, 22 semi-structured interviews were conducted with road traffic injury prevention experts from five OECD countries. In addition, 31 professional road traffic injury prevention stakeholders from seven OECD nations completed a self-administered, online survey. It found that there was resource limitation and inter-dependence across actors within the context of road traffic injury prevention at a local level. Furthermore, this study unveiled the realization of resource-dependency as a trigger for coordinated responses at a local level. Moreover, the present examination has revealed two coordinating strategies favored by experts in road traffic injury prevention – i.e. self-organizing community groups, which are deemed to have a platform to deliver programs within communities, and the funding of community groups to forge partnerships. However, the present study did not appear to endorse other strategies such as the formalization of coordinated responses or a legal mandate to coordinate responses. In essence, this study appears to suggest a need to manage coordinated responses from an adaptive perspective with interactions across road traffic injury prevention programs being forged on a mutual understanding of inter-dependency arising out of resource scarcity. In fact, the role of legislation and top-down national models in local level management of coordinated responses is likely to be one of identifying opportunities to interact with self-organized community groups and fund partnership-based road traffic injury prevention events.
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Abstract Purpose The aim of this case study is to describe patients' responses to nursing care following the implementation of a person-centred model in a radiation oncology department. Method An instrumental case study design utilised surveys to collect data on a range of key patient outcomes: patient satisfaction (PSS), informational issues (RSEP), quality of life (FACT_G), comfort (RTCQ), and emotional status (HADS). This occurred at the beginning of, and twelve months following, the implementation of the new model of care. Results This study demonstrated that, although adverse effects of radiotherapy continue to affect patient well-being in the latter part of their course of radiation therapy, patients continue to be satisfied with nursing care. There were significant differences between groups in perceptions of the care environment and the use of the nurse as an acknowledged source of information are noteworthy, since these variables were key targets of the new model of care. The finding that nurses were seen by the post-implementation cohort as more likely to be a source of information is an important indicator that the nurses' presence was noted by patients, and they generally reported high levels of functioning despite undergoing a curative course of radiotherapy. Conclusion The person-centred nursing approach in the radiotherapy setting has contributed to some improvements in the provision of patient care. Aspects of this study may assist in planning further nursing interventions for patients undergoing radiotherapy for cancer, and continue to enhance the contribution of the radiation oncology nurse to improved patient outcomes.
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Ultra-endurance exercise, such as an Ironman triathlon, induces muscle damage and a systemic inflammatory response. As the resolution of recovery in these parameters is poorly documented, we investigated indices of muscle damage and systemic inflammation in response to an Ironman triathlon and monitored these parameters 19 days into recovery. Blood was sampled from 42 well-trained male triathletes 2 days before, immediately after, and 1, 5 and 19 days after an Ironman triathlon. Blood samples were analyzed for hematological profile, and plasma values of myeloperoxidase (MPO), polymorphonuclear (PMN) elastase, cortisol, testosterone, creatine kinase (CK) activity, myoglobin, interleukin (IL)-6, IL-10 and high-sensitive C-reactive protein (hs-CRP). Immediately post-race there were significant (P < 0.001) increases in total leukocyte counts, MPO, PMN elastase, cortisol, CK activity, myoglobin, IL-6, IL-10 and hs-CRP, while testosterone significantly (P < 0.001) decreased compared to prerace. With the exception of cortisol, which decreased below prerace values (P < 0.001), these alterations persisted 1 day post-race (P < 0.001; P < 0.01 for IL-10). Five days post-race CK activity, myoglobin, IL-6 and hs-CRP had decreased, but were still significantly (P < 0.001) elevated. Nineteen days post-race most parameters had returned to prerace values, except for MPO and PMN elastase, which had both significantly (P < 0.001) decreased below prerace concentrations, and myoglobin and hs-CRP, which were slightly, but significantly higher than prerace. Furthermore, significant relationships between leukocyte dynamics, cortisol, markers of muscle damage, cytokines and hs-CRP after the Ironman triathlon were noted. This study indicates that the pronounced initial systemic inflammatory response induced by an Ironman triathlon declines rapidly. However, a low-grade systemic inflammation persisted until at least 5 days post-race, possibly reflecting incomplete muscle recovery.
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Background Most patients with minor stroke are discharged directly home from acute care, under the assumption that little will be required in the way of adaptation and adjustment because informal caregivers will manage the stroke recovery process. We explored male patients with minor stroke and their wife-caregivers' perceptions of factors affecting quality of life and caregiver strain encountered during the first year post-discharge. Methods Data were obtained from responses to two open-ended questions, part of quality of life and caregiver strain scales administered to participants in a larger descriptive study. Conventional content analysis was used to assess narrative accounts of living with minor stroke provided by 26 male patients and their wife-caregivers over a period of 1-year post-discharge. Results Two major themes that emerged from these data were 'being vulnerable' and 'realization'. Subthemes that arose within the vulnerability theme included changes to patients' masculine image and wife-caregivers' assumption of a hyper-vigilance role. In terms of 'realization' patients and their wife-caregivers shared 'loss' as well as 'changing self and relationships'. Patients in this study focused primarily on their physical recovery and their perceptions of necessary changes. Wife-caregivers were actively involved in managing the day-to-day demands that stroke placed on individual, family and social roles. Conclusions We conclude that patients and wife-caregivers expend considerable time and energy reestablishing control of their lives following minor stroke in an attempt to incorporate changes to self and their relationship into the fabric of their lives.
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Objetivo Comparar los cambios antropométricos y bioquímicos en personas inactivas, que realizan un programa de actividad física frente a los que no lo realizan desde los Centros de Atención Primaria. Métodos Cien personas inactivas de ambos sexos, mayores de 55 años fueron aleatorizadas a un grupo experimental (n = 50) y a un grupo control (n = 50). Se realizó un programa de promoción de actividad física siguiendo los criterios del Colegio Americano de Medicina del Deporte, de 60 min cada sesión, 2 sesiones por semana, durante 3 meses. Las medidas antropométricas incluyeron el índice de masa corporal y el porcentaje graso, y como variables bioquímicas el perfil lipídico, hematíes y la creatina kinasa. Resultados Completaron el estudio 75 personas. Esta investigación no presentó cambios significativos a nivel antropométrico, ni en las variables bioquímicas del perfil lipídico. Sí se observaron efectos clínicamente relevantes en la concentración de los hematíes de las mujeres que realizaron dicho programa. Conclusiones El efecto clínico global fue pequeño en las personas que realizaron el programa, pero relevante para la salud de la población. Esta intervención produce efectos a corto plazo en la bioquímica de las personas inactivas. Abstract in English Objective Compare anthropometry and biochemical changes in inactive people who participate in a physical activity program versus those who do not from the Primary Health Care Centers. Methods One hundred inactive subjects of both genders, 55 years and older, from Torremolinos, Spain were randomized into an experimental group (n = 50) and a control group (n = 50). A program promoting physical activity was carried out following the American Medical Society for Sport's Medicine criteria. The program included sessions a week for 3 months. Antropometric measurements included body mass index and fat percentage, and such as biochemical measures: the lipid profile, erythrocytes, and creatine kinase. Results Seventy-five persons completed the study. This research did not show significant changes to anthropometric or biochemical outcomes of the lipid profile. However, there were clinically relevant effects regarding red blood cells concentration in the women who participated in this program. Conclusions Overall clinical effect was small in those participating in the program, but relevant for the health of the population. This program has short-term effects on biochemistry results of inactive subjects.
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Industry clockspeed has been used in earlier literature to assess the rate of change of industries but this measure remains limited in its application in longitudinal analyses as well as in systemic industry contexts. Nevertheless, there is a growing need for such a measure as business ecosystems replace standalone products and organisations are required to manage their innovation process in increasingly systemic contexts. In this paper, we firstly derive a temporal measure of technological industry clockspeed, which evaluates the time between successively higher levels of performance in the industry's product technology, over time. We secondly derive a systemic technological industry clockspeed for systemic industry contexts, which measures the time required for a particular sub-industry to utilise the level of technological performance that is provisioned by another, interdependent sub-industry. In turn, we illustrate the use of these measures in an empirical study of the systemic personal computer industry. The results of our empirical illustration show that the proposed clockspeeds together provide informative measures of the pace of change for sub-industries and systemic industry. We subsequently discuss the organisational considerations and theoretical implications of the proposed measures.
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Cognitive scientists were not quick to embrace the functional neuroimaging technologies that emerged during the late 20th century. In this new century, cognitive scientists continue to question, not unreasonably, the relevance of functional neuroimaging investigations that fail to address questions of interest to cognitive science. However, some ultra-cognitive scientists assert that these experiments can never be of relevance to the study of cognition. Their reasoning reflects an adherence to a functionalist philosophy that arbitrarily and purposefully distinguishes mental information-processing systems from brain or brain-like operations. This article addresses whether data from properly conducted functional neuroimaging studies can inform and subsequently constrain the assumptions of theoretical cognitive models. The article commences with a focus upon the functionalist philosophy espoused by the ultra-cognitive scientists, contrasting it with the materialist philosophy that motivates both cognitive neuroimaging investigations and connectionist modelling of cognitive systems. Connectionism and cognitive neuroimaging share many features, including an emphasis on unified cognitive and neural models of systems that combine localist and distributed representations. The utility of designing cognitive neuroimaging studies to test (primarily) connectionist models of cognitive phenomena is illustrated using data from functional magnetic resonance imaging (fMRI) investigations of language production and episodic memory.
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As research encompassing neuroimaging and genetics gains momentum, extraordinary information will be uncovered on the genetic architecture of the human brain. However, there are significant challenges to be addressed first. Not the least of these challenges is to accomplish the sample size necessary to detect subtle genetic influences on the morphometry and function of the healthy brain. Aside from sample size, image acquisition and analysis methods need to be refined in order to ensure optimum sensitivity to genetic and complementary environmental influences. Then there is the vexing issue of interpreting the resulting data. We describe how researchers from the east coast of Australia and the west coast of America have embarked upon a collaboration to meet these challenges using data currently being collected from a large-scale twin study, and offer some opinions about future directions in the field.
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Process variability in pollutant build-up and wash-off generates inherent uncertainty that affects the outcomes of stormwater quality models. Poor characterisation of process variability constrains the accurate accounting of the uncertainty associated with pollutant processes. This acts as a significant limitation to effective decision making in relation to stormwater pollution mitigation. The study undertaken developed three theoretical scenarios based on research findings that variations in particle size fractions <150µm and >150µm during pollutant build-up and wash-off primarily determine the variability associated with these processes. These scenarios, which combine pollutant build-up and wash-off processes that takes place on a continuous timeline, are able to explain process variability under different field conditions. Given the variability characteristics of a specific build-up or wash-off event, the theoretical scenarios help to infer the variability characteristics of the associated pollutant process that follows. Mathematical formulation of the theoretical scenarios enables the incorporation of variability characteristics of pollutant build-up and wash-off processes in stormwater quality models. The research study outcomes will contribute to the quantitative assessment of uncertainty as an integral part of the interpretation of stormwater quality modelling outcomes.
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Recent research on hollow flange beams has led to the development of an innovative rectangular hollow flange channel beam (RHFCB) for use in floor systems. The new RHFCB is a mono-symmetric structural section made by intermittently rivet fastening two torsionally rigid closed rectangular hollow flanges to a web plate element, which allows section optimisation by selecting appropriate combinations of web and flange widths and thicknesses. However, the current design rules for cold-formed steel sections are not directly applicable to rivet fastened RHFCBs. To date, no investigation has been conducted on their web crippling behaviour and strengths. Hence an experimental study was conducted to investigate the web crippling behaviour and capacities of rivet fastened RHFCBs under End Two Flange (ETF) and Interior Two Flange (ITF) load cases. It showed that RHFCBs failed by web crippling, flange crushing and their combinations. Comparison of ultimate web crippling capacities with the predictions from the design equations in AS/NZS 4600 and AISI S100 showed that the current design equations are unconservative for rivet fastened RHFCB sections under ETF and ITF load cases. Hence new equations were proposed to determine the web crippling capacities of rivet fastened RHFCBs. These equations can also be used to predict the capacities of RHFCBs subject to combined web crippling and flange crushing conservatively. However, new capacity equations were proposed in the case of flange crushing failures that occurred in thinner flanges with smaller bearing lengths. This paper presents the details of this web crippling experimental study of RHFCB sections and the results.
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Common to many types of water and wastewater is the presence of sodium ions which can be removed by desalination technologies, such as reverse osmosis and ion exchange. The focus of this investigation was ion exchange as it potentially offered several advantages compared to competing methods. The equilibrium and column behaviour of a strong acid cation (SAC) resin was examined for the removal of sodium ions from aqueous sodium chloride solutions of varying normality as well as a coal seam gas water sample. The influence of the bottle-point method to generate the sorption isotherms was evaluated and data interpreted with the Langmuir Vageler, Competitive Langmuir, Freundlich, and Dubinin-Astakhov models. With the constant concentration bottle point method, the predicted maximum exchange levels of sodium ions on the resin ranged from 61.7 to 67.5 g Na/kg resin. The general trend was that the lower the initial concentration of sodium ions in the solution, the lower the maximum capacity of the resin for sodium ions. In contrast, the constant mass bottle point method was found to be problematic in that the isotherm profiles may not be complete, if experimental parameters were not chosen carefully. Column studies supported the observations of the equilibrium studies, with maximum sodium loading of ca. 62.9 g Na/kg resin measured, which was in excellent agreement with the predictions of the data from the constant concentration bottle point method. Equilibria involving coal seam gas water were more complex due to the presence of sodium bicarbonate in solution, albeit the maximum loading capacity for sodium ions was in agreement with the results from the more simple sodium chloride solutions.