250 research outputs found
Apomixis in Taraxacum : an embryological and genetic study = Apomixie in Taraxacum : een embryologische en genetische studie
No full textApomixis is asexual plant reproduction through seeds that are produced with no prior genome reduction or fertilisation. The use of apomixis holds enormous potential for future plant breeding and production. The outcome of the research described in this thesis suggests that the genetic basis for apomixis in Taraxacum (dandelions) comprises three major dominant genes whose timely expression may be influenced by modifier genes. Its also suggests that genome interactions effect successful establishment of apomixis in polyploid hybrids of sexual x apomictic dandelions. The work consisted of cytogenetic and embryological studies performed at the Laboratory of Genetics, Wageningen University, and the analysis of inheritance of apomixis in sexual x apomict crossings performed at the Netherlands Institute of Ecology, Centre for Terrestrial Ecology, (NIOO-CTO), Heteren, the Netherlands. A theoretical model for the Taraxacum type of apomixis is described. As a conclusion, we discuss several aspects of the evolution of apomixis in Taraxacum which serve to explain why Taraxacum is a very successful genus.</p
Ergonomic Exoskeleton Synthesis: Application to a Wearable Passive Exoskeleton for the Shoulder
No full textThe human machine-interface is more important than ever in the field of exoskeletons. Current design approaches lack a way of systematically designing the ergonomics of exoskeletons. Methods with a more pro active approach to ergonomics have to be developed. This thesis extends existing methods by which self aligning mechanisms are created with a systematic approach. A synthesis method is proposed by which all possibilities are synthesized. These possibilities are then excluded based on kinematic requirements on the system. The remaining possibilities are optimized based on ergonomic guidelines to obtain a set of solutions from which the designer can make well founded design choices. A force-deflection analysis was performed on the resulting solutions. This proposed method is applied to a planar passive exoskeleton for the shoulder. The method was successfully applied by using the total link length, reachable workspace, distance to the body and singularity avoidance as objectives for the optimization. Stiffness was added to the joints to obtain the required force-deflection behavior. The resulting objective values were verified by means of a prototype. The test results showed to be within reasonable bounds to verify the method for the planar case. The force-deflection analysis showed results that can be achieved by linear springs. This has to be verified by additional tests. The proposed method can be used as a tool in future exoskeleton design and can be extended with additional objective functions and constraints and can be extended to the three dimensional case
Effect of airbrush type on sprayed platinum and platinum-cobalt catalyst inks: benchmarking as PEMFC and performance in an electrochemical hydrogen pump
No full textProton-exchange membrane fuel cells and electrochemical hydrogen pumps are based on membrane electrode assemblies containing Pt catalysts. During their preparation, a catalyst ink is usually applied to the gas diffusion layer. Among the available methods, ink spray using an airbrush can be advantageous for making small electrodes at universities and companies. This work compares the suitability of gravity-feed and suction-feed airbrushes during the evaluation of in-house developed Pt and Pt-Co catalysts. The surface morphology of the catalyst layers was analysed by SEM and EDS and related to the preparation technique. The catalysts were compared against an off-the-shelf catalyst. The in-house Pt catalyst afforded similar polarization curves as the commercial catalyst whereas the Pt-Co catalyst exhibited a slightly inferior performance. The suction-feed airbrush was deemed preferable because its produced cracked mud-like, homogeneous and smoother catalyst layers in contrast to the gravity-feed method, which resulted in poor-quality deposits with loose particles, lower Pt utilisation and higher resistance
Brass Multiphonics in Jazz
No full textMultiphonics is the production of more than one tone at a time from an
instrument that would normally play a single line. The aim of this work is to
identify and explore the elements of multiphonics as played by jazz brass
players and to examine the production and development of multiphonics
with particular reference to Albert Mangelsdorff’s mature technique. The
research procedure includes a literature review, transcription and analysis
of relevant music, and reflection on personal practice. The findings and
discussion are used to draw conclusions in order to derive applicable
testable techniques. The research points to where the accretion and
extension of Mangelsdorff’s playing style may lead, and demonstrates the
acquisition of discovered multiphonic techniques by the performance of
transcriptions and new or extended musical applications of multiphonics in
two recorded assessed recitals.
The body of the paper gives brief biographical information on the main
practitioners, with specific focus on how each of them acquired particular
technical elements. Reference is made to prior research and specific
recordings and players are mentioned in regard to their innovations and
stylistic techniques. Elements were discovered and explored in the
researcher’s own practice over the previous decade and specifically the
duration of the masters study from February 2008 – June 2009, and the
effects of various approaches and exercises are discussed. This discussion
includes the areas of mental and physical preparation, limitations and
parameters of the physical playing, and the method used for developing
multiphonic technique.
The summary identifies the main findings and makes specific reference to
how they might relate to practice. It suggests areas where further research
can be developed to support the acquisition and practical application of
multiphonic technique and extended techniques in brass performance.
The work is presented as a paper and accompanying DVD that demonstrates
findings as played by the researcher in live recitals
Technological intensity as a moderating variable for the intellectual capital-performance relationship
No full textThe purpose of this study is to provide empirical evidence of the moderating influence of technology intensity on the relationship between intellectual capital (IC) and corporate performance in Italian small- and medium-sized enterprises (SMEs). An empirical analysis was developed for the period 2012–2016 and included 62,849 Italian SMEs. Data were collected from the AIDA database (Bureau Van Dijk—A Moody's Analytics Company), and the sample was composed of high-tech, medium-high-tech, medium-low-tech, and low-technology manufacturing firms, according to the “Classification of Manufacturing Industries by Technological Intensity,” as defined by the OECD. The empirical results highlight that profitability is significantly and positively affected by financial and physical capital efficiency and by human capital efficiency (HCE), but the effect of HCE is weak, and the structural capital efficiency has a negative effect on corporate performance. The time variables positively affect corporate performance, with the highest coefficient in 2016. Additionally, technology intensity reinforces the positive effect of HCE on firm performance: the higher the technological intensity, the higher the positive impact of HCE on corporate performance. The managerial implications are relevant; in fact, tangible, financial, and current assets (employed capital) represent the principal lever of performance for managers in technology sectors. The negative effect of structural capital could be caused by inefficient use of this resource, or the employed variable could not be adequate to effectively measure this IC component. It is necessary for managers to appreciate technological intensity as a contingency variable affecting the IC–performance relationship
ESSKA Instructional Course Lecture Book : Geneva 2012
No full textThis book contains a collection of instructional course lectures given during the 15th ESSKA (European Society of Sports Traumatology, Knee Surgery and Arthroscopy) Congress, held in Geneva during May 2012. The lectures cover a wide range of hot topics in the field, including diverse injuries and management techniques. Each lecture has a practical focus and provides an up-to-date synthesis of core knowledge on the subject in question with the aid of high-quality illustrations. Take home messages and key recommendations are highlighted. This book will be of value to practitioners and researchers alike
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Doctoral thesis recital (trombone), chamber
No full textNana / Manuel de Falla ; arranged by Ben Van Dijk (Mallory McHenry, Harp) -- Maracatu : for trombone and piano / Eloa Goncalves (Bogum Park, piano) -- Balcanius / Raphael Ferreira (Bogum Park, piano ; Cy Miessler, marimba) -- Visions / Frank Gulino (Joshua Hernandez, Nat Hsu, Luciano Vacca, Eden Garza, Lauren Casey-Clyde, trombones) -- Four pieces for brass quintet / Paquito D'Rivera (Ross Brown, Joseph Bermea, trumpets ; Jessica Chia-yian Lin, horn ; Nick Beltchev, tuba) -- Allusions / John Cheetham -- Lament / J. J. Johnson ; arrange by Slide Hampton -- Fly me to the moon / Bart Howard ; arranged by Robert Hughes -- [Unidentified piece for solo trombone]MusicName of supervisor unavailabl
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