Planar defects in ZnO thin films deposited on optical fibers and flat substrates

The microstructure and the defects of ZnO coatings deposited at room temperature by sputtering onto fibers and flat substrates were characterized using transmission electron microscopy (TEM), scanning electron microscopy, and x-ray diffraction (XRD). XRD shows that the films have a [0001] preferred orientation and a large angular width of the 0002 reflection. According to TEM observations, the film microstructure consists of columnar grains which contain large concentrations of basal planar defects and dislocations. High-resolution transmission electron microscopy analysis and the associated image simulation are in full agreement with the presence of single (type I) and double (type II) stacking faults. The relation between the observed defects and the 0002 peak broadening is discusse

Using a differential test battery to illustrate a multi-dimensional theory of intelligence

This study sets out to examine the premises of differential validity, or the use of score differences and patterns as predictors. This presupposes a view of ability or intellect as multidimensional, and therefore regards multidimensional patterns or profiles of scores, in addition to or irrespective of the actual levels of single test scores or weighted composites, as having predictive or classificatory uses. The advantages of taking a multidimensional view of intellect as assessed by differential testing are contrasted with the advantages of a unitary approach to intelligent performance, which assumes that a test or weighted test composite must be used to create a single index of performance. The study also considers the possibility that psychometric testing, as it is commonly used in selection and development, over stresses levels of performance and under-utilises the amount of information that can be gained from studying patterns of test scores. The differential test battery which is examined, the Morrisby Profile, is standardised and validated as part of this study by the author while working for the Morrisby Organisation, except where the assistance of others is specifically acknowledged. Methods for validating it both as a traditional and as a differential battery are examined, and various possible indices of differential efficiency are discussed, using multiple regression, discriminant function analysis and MANOVA. A further method is devised and presented for displaying the differential performance of a battery, using deviation scores. As deviation scores have the effect of making the measure at least partly ipsative, some issues of ipsativity are addressed, and arguments presented to justify the use of statistical techniques with partially ipsative data. Data is presented to show the relative effectiveness of different indices of validity, employing multiple regression, discriminant function analysis, MANOVA and the use of deviation scores. Although coefficients based on differentials alone rarely equal those based on score levels, combined coefficients are more effective than either, and their use is advocated. It is also argued that there may be real, if less easily quantifiable, advantages to the differential manner of presentation, with particular reference to groups commonly disadvantaged by traditional tests, especially in the field of development and guidance. The data sets examined included occupational groups, (engineers, technicians, managers, careers guidance officers and teachers), school students with academic criteria, applicants for engineering technician posts, insurance salespeople and managers whose promotional ratings had been assessed. Both categorical and noncategorical criteria are used. The battery is found to be an effective measure in both a traditional and a differential sense, although against the criteria available it is not possible to establish the absolute superiority of the differential approach in terms of predictive validity in the absence of all information relating to level of scores. It is shown that, when scalar and differential methods are combined, more of the variance is explained than when either method is used alone. In view of the possible disadvantages of traditional validation methods, it is suggested that there would be social advantages in utilising a differential method of testing. The implications of differential testing in the context of current perceptions of human abilities are discussed, and possible developments for a differential approach are indicated

Using a differential test battery to illustrate a multi-dimensional theory of intelligence

This study sets out to examine the premises of differential validity, or the use of score differences and patterns as predictors. This presupposes a view of ability or intellect as multidimensional, and therefore regards multidimensional patterns or profiles of scores, in addition to or irrespective of the actual levels of single test scores or weighted composites, as having predictive or classificatory uses. The advantages of taking a multidimensional view of intellect as assessed by differential testing are contrasted with the advantages of a unitary approach to intelligent performance, which assumes that a test or weighted test composite must be used to create a single index of performance. The study also considers the possibility that psychometric testing, as it is commonly used in selection and development, over stresses levels of performance and under-utilises the amount of information that can be gained from studying patterns of test scores. The differential test battery which is examined, the Morrisby Profile, is standardised and validated as part of this study by the author while working for the Morrisby Organisation, except where the assistance of others is specifically acknowledged. Methods for validating it both as a traditional and as a differential battery are examined, and various possible indices of differential efficiency are discussed, using multiple regression, discriminant function analysis and MANOVA. A further method is devised and presented for displaying the differential performance of a battery, using deviation scores. As deviation scores have the effect of making the measure at least partly ipsative, some issues of ipsativity are addressed, and arguments presented to justify the use of statistical techniques with partially ipsative data. Data is presented to show the relative effectiveness of different indices of validity, employing multiple regression, discriminant function analysis, MANOVA and the use of deviation scores. Although coefficients based on differentials alone rarely equal those based on score levels, combined coefficients are more effective than either, and their use is advocated. It is also argued that there may be real, if less easily quantifiable, advantages to the differential manner of presentation, with particular reference to groups commonly disadvantaged by traditional tests, especially in the field of development and guidance. The data sets examined included occupational groups, (engineers, technicians, managers, careers guidance officers and teachers), school students with academic criteria, applicants for engineering technician posts, insurance salespeople and managers whose promotional ratings had been assessed. Both categorical and noncategorical criteria are used. The battery is found to be an effective measure in both a traditional and a differential sense, although against the criteria available it is not possible to establish the absolute superiority of the differential approach in terms of predictive validity in the absence of all information relating to level of scores. It is shown that, when scalar and differential methods are combined, more of the variance is explained than when either method is used alone. In view of the possible disadvantages of traditional validation methods, it is suggested that there would be social advantages in utilising a differential method of testing. The implications of differential testing in the context of current perceptions of human abilities are discussed, and possible developments for a differential approach are indicated

Implementing tradable permits for sulfur oxides emissions : a case study in the South Coast Air Basin

Tradable emissions permits have important theoretical advantages over source-specific technical standards as a means for controlling pollution. Nonetheless, difficulties can arise in trying to implement an efficient, competitive market in emissions permits. Simple workable versions of the market concept may fail to achieve the competitive equilibrium, or to take account of important complexities in the relationship between the pattern of emissions and the geographical distribution of pollution. Existing regulatory law may severely limit the range of market opportunities that states can adopt. This report examines the feasibility of tradable permits for controlling particulate sulfates in the Los Angeles airshed. Although the empirical part of the paper deals with a specific case, the methods developed have general applicability. Moreover, the particular market design that is proposed -- an auction process that involves no net revenue collection by the state -- has attractive features as a general model

Molecular brewing: molecular structural effects involved in barley malting and mashing

Ten barley samples containing varied protein contents were subject to malting followed by mashing to investigate molecular effects of both barley starch and starch- protein interactions on malting and mashing performances, and the underlying mechanism. Starch granular changes were examined using differential scanning calorimetry and scanning electron microscopy. The molecular fine structures of amylose and amylopectin from unmalted and malted grain were obtained using size-exclusion chromatography. The results showed that both amylose and amylopectin polymers were hydrolyzed at the same time during malting. Protein and amylose content in both unmalted and malted barley significant negatively correlated with fermentable sugar content after mashing. While protein content is currently the main criterion for choosing malting varieties, this study shows that information about starch molecular structure is also useful for determining the release of fermentable sugars, an important functional property. This provides brewers with some new methods to choose malting barley

Review: Amylopectin synthesis and hydrolysis – understanding isoamylase and limit dextrinase and their impact on starch structure on barley (Hordeum vulgare) quality

Background Starch contributes to barley grain and malt quality which in turn contributes to beer quality and flavour; through fermentable sugar profiles, rates of fermentation and Mallard reactions. Both amylopectin and amylose are enzymatically degraded to release maltose, maltotriose and higher order sugars. Scope and approach Amylopectin is highly branched [α-(1\ua0→\ua06) glycoside bond branch points] with numerous short branches while amylose is a long chained polymer with a few side branches. During grain development, the final level of branching is controlled by two enzymes namely; isoamylase and limit dextrinase (LD). Mutations in either of these genes can also result in changes to structure, content, and granule formation and size. During the malting free LD will to cleave the α-(1\ua0→\ua06) bonds but during mashing processes, bound LD is release, resulting in chains of various length available for other starch degrading enzymes to hydrolyse. Findings and conclusions While there is a good understanding of most of the individual aspects in amylopectin formation, structure and degradation; the story remains incomplete, as most of this understanding has been gained from experiments with only a limited number of barley varieties, limitations in the technology for structural measurement, and since no data is available to link structure to fermentable sugar profiles

Design and Validation of Control Interfaces for Anna

This project improves the control mechanisms for a semi-autonomous wheelchair with an assistive robotic arm system. The wheelchair is aimed at increasing the self-sufficiency of individuals with LIS. The objectives include the validation of the existing control interfaces, as well as the integration and design of new systems. The wireless brain-computer headset, used to implement the control system for navigation, is validated through several user studies. An EMG sensor system serves as an alternative control module. To increase physical interaction with the environment, a robotic arm system is integrated. The system includes a RGB-D camera for object detection, enabling autonomous object retrieval. The project outcomes include a demonstration performing navigation and manipulation tasks