873 resultados para physical selection tests
Resumo:
Site selection is a key activity for quarry expansion to support cement production, and is governed by factors such as resource availability, logistics, costs, and socio-environmental factors. Adequate consideration of all factors facilitates both industrial productivity and sustainable economic growth. This study illustrates the site selection process that was undertaken for the expansion of limestone quarry operations to support cement production in Barbados. First, alternate sites with adequate resources to support a 25-year development horizon were identified. Second, socio-environmental conditions were described and potential impacts identified. Third, a comparative matrix was constructed to evaluate relative site characteristics with respect to physical, ecological, socio-cultural and economic factors. The study shows that environmental factors were essential to the final site recommendation.
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This paper extends previous analyses of the choice between internal and external R&D to consider the costs of internal R&D. The Heckman two-stage estimator is used to estimate the determinants of internal R&D unit cost (i.e. cost per product innovation) allowing for sample selection effects. Theory indicates that R&D unit cost will be influenced by scale issues and by the technological opportunities faced by the firm. Transaction costs encountered in research activities are allowed for and, in addition, consideration is given to issues of market structure which influence the choice of R&D mode without affecting the unit cost of internal or external R&D. The model is tested on data from a sample of over 500 UK manufacturing plants which have engaged in product innovation. The key determinants of R&D mode are the scale of plant and R&D input, and market structure conditions. In terms of the R&D cost equation, scale factors are again important and have a non-linear relationship with R&D unit cost. Specificities in physical and human capital also affect unit cost, but have no clear impact on the choice of R&D mode. There is no evidence of technological opportunity affecting either R&D cost or the internal/external decision.
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This research investigates technology transfer (TT) to developing countries, with specific reference to South Africa. Particular attention is paid to physical asset management, which includes the maintenance of plant, equipment and facilities. The research is case based, comprising a main case study (the South African electricity utility, Eskom) and four mini-cases. A five level framework adapted from Salami and Reavill (1997) is used as the methodological basis for the formulation of the research questions. This deals with technology selection, and management issues including implementation and maintenance and evaluation and modifications. The findings suggest the Salami and Reavill (1997) framework is a useful guide for TT. The case organisations did not introduce technology for strategic advantage, but to achieve operational efficiencies through cost reduction, higher quality and the ability to meet customer demand. Acquirers favour standardised technologies with which they are familiar. Cost-benefit evaluations have limited use in technology acquisition decisions. Users rely on supplier expertise to compensate for poor education and technical training in South Africa. The impact of political and economic factors is more evident in Eskom than in the mini-cases. Physical asset management follows traditional preventive maintenance practices, with limited use of new maintenance management thinking. Few modifications of the technology or R&D innovations take place. Little use is made of explicit knowledge from computerised maintenance management systems. Low operating and maintenance skills are not conducive to the transfer of high-technology equipment. South African organisations acquire technology as items of plant, equipment and systems, but limited transfer of technology takes place. This suggests that operators and maintainers frequently do not understand the underlying technology, and like workers elsewhere, are not always inclined towards adopting technology in the workplace.
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This project represents the collaboration of Charta Mede Ltd and the Interdisciplinary Higher Degrees Scheme at the University of Aston. The aim of the project was to monitor the effects of the Civil Service's Executive Officer Qualifying Test Battery on minority group applicants. Prior to monitoring the EO Test Battery, however, an ethnic classification had to be developed which was reliable, acceptable to respondents and appropriate for monitoring. Three pilot studies were conducted to examine these issues, during which different classifications and different ways of asking the question were trialled. The results indicated that by providing more precise instructions as to the meanings of categories, it was possible to obtain classifications which were acceptable and reliable. However, there were also certain terms and expressions which should be avoided such as those referring to colour and anthropological racial groups. Two classifications were used in the Executive Officer Study - one derived from an Office of Population Censuses and Surveys classification and one developed for this project - the MultiCultural British Classification. The results indicated that some minority groups (Asians, West Indians and Africans in particular) pass the tests in significantly lower proportions than the majority group and also score significantly less well on the tests. Factors which were significantly related to pass/fail and test scores included educational qualifications and age on entering the UK (the latter being negatively correlated). Using variables in this study, however, it was only possible to account for 5% of the variance in pass/fail rates and 11% of the variance in test scores. Analyses of covariance carried out indicated that the differences in test scores still remained even though the effects of significantly correlated variables were removed. Although indirect discrimination could not be inferred from the data, further research into differential validity and fairer methods of select ion is needed.
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The standard reference clinical score quantifying average Parkinson's disease (PD) symptom severity is the Unified Parkinson's Disease Rating Scale (UPDRS). At present, UPDRS is determined by the subjective clinical evaluation of the patient's ability to adequately cope with a range of tasks. In this study, we extend recent findings that UPDRS can be objectively assessed to clinically useful accuracy using simple, self-administered speech tests, without requiring the patient's physical presence in the clinic. We apply a wide range of known speech signal processing algorithms to a large database (approx. 6000 recordings from 42 PD patients, recruited to a six-month, multi-centre trial) and propose a number of novel, nonlinear signal processing algorithms which reveal pathological characteristics in PD more accurately than existing approaches. Robust feature selection algorithms select the optimal subset of these algorithms, which is fed into non-parametric regression and classification algorithms, mapping the signal processing algorithm outputs to UPDRS. We demonstrate rapid, accurate replication of the UPDRS assessment with clinically useful accuracy (about 2 UPDRS points difference from the clinicians' estimates, p < 0.001). This study supports the viability of frequent, remote, cost-effective, objective, accurate UPDRS telemonitoring based on self-administered speech tests. This technology could facilitate large-scale clinical trials into novel PD treatments.
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The present study tests whether a self-affirmation intervention (i.e., requiring an individual to focus on a valued aspect of their self-concept, such as honesty) can increase physical activity and change theory of planned behavior (TPB) variables linked to physical activity. Eighty young people completed a longitudinal intervention study. Baseline physical activity was assessed using the Godin Leisure-Time Physical Activity Questionnaire (LTPAQ). Next, participants were randomly allocated to either a self-affirmation or a nonaffirmation condition. Participants then read information about physical activity and health, and completed measures of TPB variables. One week later, participants again completed LTPAQ and TPB items. At follow up, self-affirmed participants reported significantly more physical activity, more positive attitudes toward physical activity, and higher intentions to be physically active compared with nonaffirmed participants. Neither attitudes nor intentions mediated the effects of self-affirmation on physical activity. Self-affirmation can increase levels of physical activity and TPB variables. Self-affirmation interventions have the potential to become relatively simple methods for increasing physical activity levels. © 2014 Human Kinetics, Inc.
Resumo:
Site selection is a key activity for quarry expansion to support cement production, and is governed by factors such as resource availability, logistics, costs, and socio-environmental factors. Adequate consideration of all factors facilitates both industrial productivity and sustainable economic growth. This study illustrates the site selection process that was undertaken for the expansion of limestone quarry operations to support cement production in Barbados. First, alternate sites with adequate resources to support a 25-year development horizon were identified. Second, socio-environmental conditions were described and potential impacts identified. Third, a comparative matrix was constructed to evaluate relative site characteristics with respect to physical, ecological, socio-cultural and economic factors. The study shows that environmental factors were essential to the final site recommendation.
Resumo:
Light curable dimethacrylate resin composites undergo free radical photopolymerisation in response to blue light (wavelength 450-500 nm) and may offer superior handling and setting characteristics for novel hard tissue repair materials. The current investigation aims to determine the optimum formulation of bisphenol-A glycidyl methacrylate and triethyleneglycoldimethacrylate (bisGMA/TEGDMA) or urethane dimethacrylate (UDMA)/TEGDMA resin mixtures and the effect of Bioglass incorporation on the rate of polymerisation (RP), degree of conversion (DC) and flexural strength (FS) of light-curable filled resin composites (FRCs). Experimental photoactive resins containing a range of bisGMA, UDMA and TEGDMA ratios and/or filled with non-silanised irregular or spherical 45S5-Bioglass (50 μm; 5-40 wt%) and/or silanised silicate glass filler particulates (0.7 μm; 50-70 wt%) were tested. RP and DC were analysed in real-time using nearinfrared spectroscopy. FS of resins and FRCs were determined using three-point flexural strength tests. UDMA/TEGDMA resins exhibited increased DC compared with bisGMA/TEGDMA resins (p<0.05). The addition of spherical particles of Bioglass had a detrimental effect on the FS (p>0.05), whereas they increased DC of UDMA/TEGDMA resins (p<0.05). Addition of irregular shaped Bioglass particles increased the FS of UDMA/TEGDMA resins up to 20 wt% Bioglass (p<0.05). The flexibility and strength conferred by the urethane group in UDMA may result in enhanced physical and mechanical properties compared with conventional resins containing bulky (bisGMA) molecules. Addition of 45S5-Bioglass with specific filler content, size and morphology resulted in enhanced mechanical and physical properties of UDMA/TEGDMA composites. © (2014) Trans Tech Publications, Switzerland.
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Objectives Understanding the impact of the counterion on the properties of an acidic or basic drug may influence the choice of salt form, especially for less potent drugs with a high drug load per unit dose. The aim of this work was to determine the influence of the hydrogen bonding potential of the counterion on the crystal structure of salts of the poorly soluble, poorly compressible, acidic drug gemfibrozil and to correlate these with mechanical properties. Methods Compacts of the parent drug and the salts were used to determine Young's modulus of elasticity using beam bending tests. Crystal structures were determined previously from X-ray powder diffraction data. Key findings The free acid, tert-butylamine, 2-amino-2-methylpropan-1-ol and 2-amino-2-methylpropan-1, 3-diol salts had a common crystal packing motif of infinite hydrogen-bonded chains with cross-linking between pairs of adjacent chains. The tromethamine (trsi) salt, with different mechanical properties, had a two-dimensional sheet-like network of hydrogen bonds, with slip planes, forming a stiffer compact. Conclusions The type of counter ion is important in determining mechanical properties and could be selected to afford slip and plastic deformation. © 2010 Royal Pharmaceutical Society of Great Britain.
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The purpose of this study was to determine fifth grade students' perceptions of the Fitnessgram physical fitness testing program. This study examined if the Fitnessgram physical fitness testing experience promotes an understanding of the health-related fitness components and examined the relationship between individual fitness test scores and time spent participating in out-of-school physical activity. Lastly, students' thoughts and feelings concerning the Fitnessgram experience were examined. ^ The primary participant population for the study was 110 fifth grade students at Redland Elementary School, a Miami-Dade County Public School (M-DCPS). Data were collected over the course of 5 months. Multiple sources of data allowed for triangulation. Data sources included Fitnessgram test scores, questionnaires, document analysis, and in-depth interviews. ^ Interview data were analyzed qualitatively for common broad themes, which were identified and defined. Document analysis included analyzing student fitness test scores and student questionnaire data. This information was analyzed to determine if the Fitnessgram test scores have an impact on student views about the school fitness-testing program. Data were statistically analyzed using analysis of frequency, crosstabulations (Bryman & Duncan, 1997), and Somers'd Correlation (Bryman & Duncan, 1997). The results of the analysis of data on student knowledge of the physical fitness components tested by each Fitnessgram test revealed students do not understand the health-related fitness components. ^ The results of determining a relationship between individuals' fitness test scores and time spent in out-of-school physical activity revealed a significant positive relationship for 2 of the 6 Fitnessgram tests. ^ The results of examining students' thoughts and feelings about each Fitnessgram test focused around 2 broad themes: (a) these children do not mind the physical fitness testing and (b) how they felt about the experience was directly related to how they thought they had performed. ^ If the goal of physical fitness was only to get children fit, this test may be appropriate. However, the ultimate goal of physical fitness is to encourage students to live active and healthy lifestyles. Findings suggest the Fitnessgram as implemented by M-DCPS may not be the most suitable measurement instrument when assessing attitudinal changes that affect a healthy lifelong lifestyle. ^
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This study examined the relationships between gifted selection criteria used in the Dade County Public Schools of Miami, Florida and performance in sixth grade gifted science classes.^ The goal of the study was to identify significant predictors of performance in sixth grade gifted science classes. Group comparisons of performance were also made. Performance in sixth grade gifted science was defined as the numeric average of nine weeks' grades earned in sixth grade gifted science classes.^ The sample consisted of 100 subjects who were formerly enrolled in sixth grade gifted science classes over two years at a large, multiethnic public middle school in Dade County.^ The predictors analyzed were I.Q. score (all scales combined), full scale I.Q. score, verbal scale I.Q. score, performance scale I.Q. score, combined Stanford Achievement Test (SAT) score (Reading Comprehension plus Math Applications), SAT Reading Comprehension score, and SAT Math Applications score. Combined SAT score and SAT Math Applications score were significantly positively correlated to performance in sixth grade gifted science. Performance scale I.Q. score was significantly negatively correlated to performance in sixth grade gifted science. The other predictors examined were not significantly correlated to performance.^ Group comparison results showed the mean average of nine weeks grades for the full scale I.Q. group was greater than the verbal and performance scale I.Q. groups. Females outperformed males to a highly significant level. Mean g.p.a. for ethnic groups was greatest for Asian students, followed by white non-Hispanic, Hispanic, and black. Students not receiving a lunch subsidy outperformed those receiving subsidies.^ Comparisons of performance based on gifted qualification plan showed the mean g.p.a. for traditional plan and Plan B groups were not different. Mean g.p.a. for students who qualified for gifted using automatic Math Applications criteria was highest, followed by automatic Reading Comprehension criteria and Plan B Matrix score. Both automatic qualification groups outperformed the traditional group. The traditional group outperformed the Plan B Matrix group. No significant differences in mean g.p.a. between the Plan B subgroups and the traditional plan group were found. ^
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A plethora of recent literature on asset pricing provides plenty of empirical evidence on the importance of liquidity, governance and adverse selection of equity on pricing of assets together with more traditional factors such as market beta and the Fama-French factors. However, literature has usually stressed that these factors are priced individually. In this dissertation we argue that these factors may be related to each other, hence not only individual but also joint tests of their significance is called for. ^ In the three related essays, we examine the liquidity premium in the context of the finer three-digit SIC industry classification, joint importance of liquidity and governance factors as well as governance and adverse selection. Recent studies by Core, Guay and Rusticus (2006) and Ben-Rephael, Kadan and Wohl (2010) find that governance and liquidity premiums are dwindling in the last few years. One reason could be that liquidity is very unevenly distributed across industries. This could affect the interpretation of prior liquidity studies. Thus, in the first chapter we analyze the relation of industry clustering and liquidity risk following a finer industry classification suggested by Johnson, Moorman and Sorescu (2009). In the second chapter, we examine the dwindling influence of the governance factor if taken simultaneously with liquidity. We argue that this happens since governance characteristics are potentially a proxy for information asymmetry that may be better captured by market liquidity of a company's shares. Hence, we jointly examine both the factors, namely, governance and liquidity - in a series of standard asset pricing tests. Our results reconfirm the importance of governance and liquidity in explaining stock returns thus independently corroborating the findings of Amihud (2002) and Gompers, Ishii and Metrick (2003). Moreover, governance is not subsumed by liquidity. Lastly, we analyze the relation of governance and adverse selection, and again corroborate previous findings of a priced governance factor. Furthermore, we ascertain the importance of microstructure measures in asset pricing by employing Huang and Stoll's (1997) method to extract an adverse selection variable and finding evidence for its explanatory power in four-factor regressions.^
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Corvio sandstone is a ~20 m thick unit (Corvio Formation) that appears in the top section of the Frontada Formation (Campoó Group; Lower Cretaceous) located in Northern Spain in the southern margin of the Basque-Cantabrian Basin. Up to 228 plugs were cored from four 0.3 x 0.2 x 0.5 m blocks of Corvio sandstone, to perform a comprehensive characterization of the physical, mineralogical, geomechanical, geophysical and hydrodynamic properties of this geological formation, and the anisotropic assessment of the most relevant parameters. Here we present the first data set obtained on 53 plugs which covers (i) basic physical and chemical properties including density, porosity, specific surface area and elementary analysis (XRF - CHNS); (ii) the curves obtained during unconfined and confined strengths tests, the tensile strengths, the calculated static elastic moduli and the characteristic stress levels describing the brittle behaviour of the rock; (iii) P- and S-wave velocities (and dynamic elastic moduli) and their respective attenuation factors Qp and Qs, electrical resistivity for a wide range of confining stress; and (iv) permeability and transport tracer tests. Furthermore, the geophysical, permeability and transport tests were additionally performed along the three main orthogonal directions of the original blocks, in order to complete a preliminary anisotropic assessment of the Corvio sandstone.
Resumo:
The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.