395 research outputs found
Vapor-liquid equilibria of a low GWP refrigerant, R-1234ze(E), mixed with a POE lubricant
No full textNovel vapor-liquid-equilibria data (P-T-x) and liquid densities of binary mixtures of an emerging low-GWP (Global Warming Potential) refrigerant, R-1234ze(E), and a polyol ester (POE) oil, RL68H, are measured. Data are presented for oil mass fractions ranging from 0 to 0.85 over a temperature range from -10 to 60°C, and the results are compared to the properties of mixtures of R-134a with RL68H.
In addition to providing new pure-refrigerant and refrigerant/oil property data, a comparison of the performance of five mixture models is undertaken, namely: the Wilson model, NRTL, UNIQUAC, Heil, and Raoult’s law. Overall, the Heil model provides the best agreement in pressure predictions for R-1234ze(E)/RL68H mixtures, with RMS deviations less than 0.5%, while NRTL RMS deviations are less than 1%. However, comparable performance was found for the much simpler Raoult’s law, with increased deviations at the highest oil concentration. Model sensitivity and applicability of Raoult’s law for refrigerant/oil mixtures in general are investigated.
The experimental data and modeling results presented are especially valuable for engineers working in the automotive air-conditioning and refrigeration industries. The refrigerant R-1234ze(E) is one of the leading alternatives for replacing R-134a and is a member of the HFO family of chemicals that includes other low-GWP refrigerants. Accurate models for the new refrigerants and refrigerant/oil mixtures are essential for designing and analyzing refrigeration and air-conditioning systems with reduced environmental impact.Submission published under a 24 month embargo labeled 'U of I only', the embargo will last until 2017-08-01The student, Jessica Bock, accepted the attached license on 2015-07-13 at 15:06.The student, Jessica Bock, submitted this Dissertation for approval on 2015-07-13 at 15:15.This Dissertation was approved for publication on 2015-07-17 at 07:29.DSpace SAF Submission Ingestion Package generated from Vireo submission #8434 on 2015-09-29 at 14:59:29Made available in DSpace on 2015-09-29T20:49:56Z (GMT). No. of bitstreams: 2
BOCK-DISSERTATION-2015.pdf: 2044592 bytes, checksum: 2a60c529f417d3fa147c05cd1c7d3444 (MD5)
LICENSE.txt: 4209 bytes, checksum: fa9f7009692e22b136add069f46ef6f2 (MD5)
Previous issue date: 2015-07-17Embargo set by: Seth Robbins for item 89468
Lift date: 2017-09-29T20:50:34Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Only Restriction Lifted for Item 89468 on 2017-09-30T09:15:38Z
Are language production problems apparent in adults who no longer meet diagnostic criteria for attention-deficit/hyperactivity disorder?
No full textIn this study, we examined sentence production in a sample of adults (N = 21) who had had attention-deficit/hyperactivity disorder (ADHD) as children, but as adults no longer met DSM-IV diagnostic criteria (APA, 2000). This “remitted” group was assessed on a sentence production task. On each trial, participants saw two objects and a verb. Their task was to construct a sentence using the objects as arguments of the verb. Results showed more ungrammatical and disfluent utterances with one particular type of verb (i.e., participle). In a second set of analyses, we compared the remitted group to both control participants and a “persistent” group, who had ADHD as children and as adults. Results showed that remitters were more likely to produce ungrammatical utterances and to make repair disfluencies compared to controls, and they patterned more similarly to ADHD participants. Conclusions focus on language output in remitted ADHD, and the role of executive functions in language production
Musical Challenges: paths taken by professional cellists in the construction of their performances
No full textEste trabalho teve como objetivo investigar a preparação para a performance musical de violoncelistas profissionais, pesquisando possibilidades de estratégias de estudo que possam gerar maior autonomia e criatividade na solução dos desafios técnicos e musicais que o repertório exige. Para tanto, além de pesquisa bibliográfica sobre processos criativos na preparação para a performance musical, foram abordados o trabalho literário, pedagógico e acadêmico de violoncelistas que refletem sobre a prática no instrumento de forma inovadora. Neste sentido, discutiu-se a busca da experiência do Fluxo e da plenitude na performance musical. Refletiu-se também sobre a necessidade dos cuidados e manutenção da saúde física, mental e emocional no cotidiano profissional. Para atingir esses objetivos, realizou-se um levantamento de práticas que vêm sendo utilizadas por músicos, paralelamente ao estudo do instrumento. Motivada pela experiência pessoal, aprofundou-se em uma reflexão sobre a prática do Qigong, elaborando-se breve histórico e pesquisa bibliográfica sobre essa arte milenar chinesa, estabelecendo relações e influências no campo da prática instrumental em geral e do violoncelo, especificamente. Finalmente, realizou-se pesquisa de campo que incluiu coleta e análise de dados a partir de um questionário respondido por 42 violoncelistas profissionais, do Brasil e do exterior. Utilizou-se a pesquisa quali-quantitativa, como metodologia de análise de dados. Foram abordadas as seguintes temáticas: o estudo do instrumento na vida profissional; estratégias de estudo utilizadas para lidar com dificuldades técnico-musicais de repertórios novos ou desafiadores; estratégias sem o uso do instrumento; principais sintomas de ansiedade de performance e estratégias de enfrentamento dos mesmos; atividades praticadas paralelamente ao estudo do instrumento, em busca de maior bem-estar físico, mental e emocional; e, por fim, influência dessas práticas no processo de preparação da performance musical. Nas considerações finais, estabeleceu-se as relações entre a pesquisa bibliográfica e a pesquisa de campo, apontando caminhos que podem inspirar estudantes, professores e outros violoncelistas profissionais.This work aims to investigate the preparation for musical performance of professional cellists, researching possibilities for study strategies that can generate greater autonomy and creativity in solving the technical and musical challenges that the repertoire requires. Therefore, in addition to bibliographical research on creative processes in the preparation of musical performance, the literary, pedagogical and academic work of cellists who reflect on the instrument\'s practice in an innovative way were approached. The search for the experience of Flow and fullness in musical performance was discussed. The author reflected on the need for care and maintenance of physical, mental and emotional health in daily professional life. To achieve these objectives, a panorama of practices that have been used by musicians was looked at, in parallel with the study of the instrument. Motivated by the personal experience of the author, the practice of Qigong was examined, offering a brief history and bibliographic research on this ancient Chinese art, establishing relationships and influences in the field of instrumental practice in general and the cello, specifically. Finally, a field survey included data collection and analysis from a questionnaire answered by 42 professional cellists, from Brazil and abroad. Quali-quantitative research was used as a data analysis methodology. The following topics were addressed: the study of the instrument in professional life; study strategies used to deal with technical-musical difficulties in new or challenging repertoires; strategies without the use of the instrument; main symptoms of performance anxiety and coping strategies; activities carried out in parallel with the study of the instrument, in search of greater physical, mental and emotional well-being; and the influence of these practices in the process of preparing a musical performance. In the final considerations, the author sought to establish relationships between bibliographic research and field research, pointing out ways that may inspire students, teachers and other professional cellists
Central state child care policies in postauthoritarian Spain: Implications for gender and carework arrangements
No full textIn Spain, public preschool programs have continuously expanded in the past three decades. However, this education policy has done little to support increases in the proportion of women in the paid workforce. Preschool is not child care because the former does not address the care needed by children younger than three years old and offers programs with short hours and long holidays.Publicad
Data-driven and physics-based modeling to utilize process-property relationships in materials mechanics and processing
No full textThermal analysis of laser additive manufacturing of aluminium alloys: Experiment and simulation
No full textCello techniques and performing practices in the nineteenth and early twentieth centuries
No full textThis thesis comprises a study of cello performance practices throughout the nineteenth century and into the early decades of the twentieth. It is organised in terms of the increasing complexity of the concepts which it examines, as they are to be found in printed and manuscript music, instrumental methods and larger treatises, early recordings, concert reviews and pictures. Basic posture is considered along with different ways of holding the
bow. The development of the tail-pin shows that even when it was widely used, the older posture was still referred to as a model. Some implications for tone quality and tonal
projection are considered in the light of the shape of the arms. Some connections between the cellist's posture and that recommended by etiquette books are explored. The
functionality of the left hand and arm, and the development of modem scale fingerings, show that there was a considerable period of overlap between newer and older practices, with modern scale fingerings evolving over a long period of time. Similarly, views on the function of the right wrist in bowing are shown to change gradually, moving towards a more active upper arm movement with less extreme flexibility of the wrist. Two central expressive techniques especially associated with string playing arc considered in the context of the cello, namely vibrato and portamento. These topics are examined in the light of written indications in music, recommendations in cello treatises, and the practices evidenced in early recordings. The sources for this study can be brought into an overall
framework of a constant dialogue between `theory', as expressed in verbal instructions to the learner, or general a priori reflections about the cello, and `practice', manifested in performing editions and early recordings, or in individual acts of reception. A wide divergence is noted, both between theory and practice in general, and in terms of different styles of playing observable at any one time. It is suggested that tensions between practice
and critical disapproval can be resolved in terms of Lacanian discourse. Several test cases are used in order to compare several different recordings of the same works. The question of the musical character of the cello is discussed in terms of widespread assumptions about its gendered identity. A wide range of sources suggest that this moved from a straightforwardly `masculine' identity expressed through a controlling, elevated eloquence to a less clearly defined one, incorporating the 'feminine', with a greater stress on uninhibited emotional expression. Some performance implications for this change of view are pursued with respect to specific repertoires. Broad conclusions stress the importance of the diversity of performance practices as opposed to unifying generalisations
Hydraulics of wells
No full textCER47-52DFP42.March 1952.Includes bibliographical references (pages 41-42).Acknowledgement is given to C. H. Zee, a graduate student in irrigation engineering, and to Dr. Robert O. Bock, associate professor of physics, both of Colorado A & M College, for making available unpublished data on the seepage face for gravity wells
Means for a future policy: “Critique of violence” by Walter Benjamin
No full textVersión al castellano de Laura FlórezEl artículo se centra en el enigmático ensayo
de Walter Benjamin “Para la crítica de
la violencia” de 1921. El autor lo interpreta
en el contexto de las ideas políticas del
movimiento juvenil alemán antes y después
de la Primera Guerra Mundial. A diferencia
de otras interpretaciones, se enfoca más en
cierta empresa política que en una forma de
expresión mesiánica, que era la lectura habitual.
Se hace evidente que Benjamin se refiere
a una acción no muy lejana, por ejemplo,
a la toma de decisión de Kierkegaard en materia
de ética. En la segunda parte, el autor
analiza algunas recientes erróneas interpretaciones
y señala las heterogéneas e intensamente
políticas conclusiones de Benjamin
para hoy en díaThe article focuses on Walter Benjamin’s
enigmatic essay Critique of Violence from
1921. The author interprets it in the context
of the political ideas of the German Youth
movement before and after the First World
War. Different from other interpretations,
he focuses more on a certain political act
than on a usual messianic way of reading. It
becomes evident that Benjamin refers to an
act not far from for example Kierkegaard’s
decision in ethics. In the second part, the
author discusses some recent misinterpretations
and points out the actuality of Benjamin’s
heterogeneous and highly political
conclusions for toda
Antitrust Policy: A Century of Economic and Legal Thinking
No full textPassage of the Sherman Act in the United States in 1890 set the stage for a century of jurisprudence regarding monopoly, cartels, and oligopoly. Among American statutes that regulate commerce, the Sherman Act is unequaled in its generality. The Act outlawed "every contract, combination or conspiracy in restraint of trade" and "monopolization" and treated violations as crimes. By these open-ended commands, Congress gave federal judges extraordinary power to draw lines between acceptable cooperation and illegal collusion, between vigorous competition and unlawful monopolization. By enlisting the courts to elaborate the Sherman Act' s broad commands, Congress gave economists a singular opportunity to shape competition policy. Because the statute' s vital terms directly implicated economic concepts, their interpretation inevitably would invite contributions from economists. What emerged is a convergence of economics and law without parallel in public oversight of business. As economic learning changed, the contours of antitrust doctrine and enforcement policy eventually would shift, as well. This article follows the evolution of thinking about competition since 1890 as reflected by major antitrust decisions and research in industrial organization. We divide the U.S. antitrust experience into five periods and discuss each period' s legal trends and economic thinking in three core areas of antitrust: cartels, cooperation, or other interactions among independent firms; abusive conduct by dominant firms; and mergers.
- …
