669 research outputs found
Mechanistic Investigations into the Palladium-Catalyzed Decarboxylative Allylic Alkylation of Ketone Enolates Using the PHOX Ligand Architecture
No full textPalladium-catalyzed asymmetric allylic alkylation has become a large and important field for chemical synthesis. Many methodologies in this field offer mild conditions under which challenging and important molecular features can be reliably synthesized, including chiral all-carbon quaternary stereocenters. As a result, palladium- catalyzed asymmetric allylic alkylation has found significant use in total synthesis, and growing use in industry. While the general process of palladium-catalyzed asymmetric allylic alkylation has been studied for decades, there have been a number of recent modifications and developments, such as asymmetric versions of decarboxylative allylic alkylation procedures that are not yet well understood. The development of future implementations and improvements to palladium-catalyzed asymmetric allylic alkylation and related methodologies is expected to be facilitated by a better understanding of these more recent developments, and thus further mechanistic investigation is warranted.
Reported herein is a set of investigations into the palladium-catalyzed decarboxylative asymmetric allylic alkylation of ketone enolates using the PHOX ligand architecture. By monitoring the reaction via 31P NMR, a series of previously unidentified key intermediates is discovered. Two representatives of these key intermediates are isolated and characterized. The solution behavior of these species under reaction-like conditions is studied along with a few novel and related complexes. The role of these intermediates and their impact on the behavior of the reaction and product formation is discussed. Previously confounding experimentally observed behavior for this methodology is rationalized via the properties elucidated for these discovered intermediates.</p
George E. Haynes, circa 1945
No full textGeorge E. Haynes (1880-1960), Class of 1903, was a sociologist, author, educator. Haynes was the first black graduate of a School of Social Work (1910) and the first black to receive a Ph.D. from Columbia University
Donald Frederick Haynes Family
No full textDonald Frederick Haynes stands with his wife Lilah Mae (Baer) and daughter Dona Louise. Pastor D. F. Haynes sang in a quartet at the 1946 General Conference Session praise service on the morning of June 14. Donald was the son of evangelist and author Carlyle Boynton Haynes.https://scholarsrepository.llu.edu/general-conference-1946-gallery/1011/thumbnail.jp
Roy Haynes: the early years
No full textIn four parts, this thesis covers the early years of the life, development, and career of Roy Haynes beginning with his ancestry and family history in Boston, to the early 1950's in New York, by which time he had become an established fixture on the scene of New York’s new evolution of African American music called bebop. The purpose of this study is to magnify the genesis of one of America’s treasured artists – taking a glimpse into the dawning of his influences and musical exposure, and later highlighting his gift in expressive versatility which carried him throughout his career, displaying the gradual making of an internationally renowned artist.
Part one is comprised of four chapters, and includes an introduction and biographical information. Chapter one covers his genealogy, taking a step back to identify the sources of his African and Caribbean roots that help to inform who he is personally and musically.
Chapter two sheds light upon his social and familial development in the historical context around and between World War I and The Great Depression. It touches upon the social, cultural, and economic existence of the immigrants who found themselves in and around the communities of Lower Roxbury. This section shows when and how Haynes’s talent emerged, and how through his gift he was able to build a sound reputation as a solid musician around New England.
From that reputation, which traveled all the way to New York, chapter three continues with Haynes’s professional career in Boston, then leaps to New York City via a one-way train ticket to join the famed Luis Russell Orchestra.
In chapter four, the author explains plans for additional research, and the continued synthesis and distillation thereof toward the eventual publication of biographical literature for both adults and children.
Continuing with part two of this work, chapter five includes musical analyses highlighting Haynes’s contributions on three particular recordings between 1945 and 1949.
In part three, chapters six through fourteen feature interview transcripts from nine individuals who provide an overview of expert insight spanning several generations on a variety of cultural, musical, and stylistic influences and contributions of Haynes’s artistry.
Finally, in part four, there are several appendices which represent visual images on topics approached throughout, and in support of the narrative.M.A.Includes bibliographical referencesby Leslie K. Hayne
FIGURE. Authors (or co-authors) of more than five currently accepted specific and infraspecific cycad taxa (author abbreviations follow Calonje et al. 2022). in Etymological compendium of cycad names
No full textFIGURE. Authors (or co-authors) of more than five currently accepted specific and infraspecific cycad taxa (author abbreviations follow Calonje et al. 2022).Published as part of Haynes, Jody L., 2022, Etymological compendium of cycad names, pp. 1-31 in Phytotaxa 550 (1) on page 5, DOI: 10.11646/phytotaxa.550.1.1, http://zenodo.org/record/663061
[[alternative]]A Study of weldability characteristic of HAYNES 230 Superalloys
No full text[[abstract]]Superalloys Haynes 230 is one of several high strength precipitated hardened Ni-base superalloys suitable for service in the high temperature range. It has excellent corrosion and oxidation resistance as well as good tensile, fatigue, and creep properties at elevated temperature. TIG welding is one of the major welding processes which give a full penetrated, high-quality weldment. There are welding problems such as hot cracking and reduction of strength in the HAZ in the Ni-base superalloys.
The objective of this research project is to determine the optimum welding parameters which can obtain full and uniform penetration of the weld fusion zone in TIG weldment of superalloys Haynes 230. Mechanical properties including tensile test and microhardness test were conducted. Metallurgical examination, X-ray analysis, and SEM observation were also used for microstructure analysis. Several heat treatments were conducted to determine the optimum condition to recovery the strength in the HAZ. In order to compare the hot cracking susceptibility of Haynes 230 and Inconel 718, a newly developed Varestraint testing machine was utilized.
From the results of Varestraint test, the total crack length increases with the increase of augmented strain. But the total crack lengths have not been affected by multiple thermal cycling. The microhardness of fusion zone with filler metal is higher than the fusion zone that without filler metal. The ductility of weldment could be enhanced by solution heat treatment but ultimate tensile strength and yield strength were decreased. After stress relief heat treatment, the ultimate tensile strength, yield strength and ductility are better than the weldment without heat treatment. From the observation of SEM fractography results, the fracture surface of cracking have displayed solidification cracking in the fusion zone and liquation cracking in the heat affected zone. The ductile fracture surface was observed in all tensile tested specimens.
Teaching Children to Think for Themselves: From Questioning to Dialogue
No full textThe methods of teaching critical thinking currently favoured are critical analysis and metacognition. The former denies the place of interactive contextual judgment in reasoning, the latter devalues human purposes and quality. A metacognitive lesson on classification is shown to be too didactic to allow children to think in any but a passive sense. Splitter’s categorization of questions shows how moving away from closed substantive questions to open ones through dialogue can encourage children to think for themselves. Some consequences for pedagogy and evaluating children’s thinking are briefly examined
Interview with Todd Haynes
No full textDistillation of three phone interviews conducted by the author on November 3 and 22, 2011, and April 17, 2012.ROB WHITE:What is your family background?TODD HAYNES:My mom, Sherry Lynne Haynes, came from a middle-class Jewish family in Los Angeles. Her father, Arnold Semler, whom I called Bompi, and mother, Blessing, whom I called Monna, were a very supportive aspect of my upbringing. Bompi had worked in Warner Bros., starting as a messenger boy, becoming head of set construction. He was a union organizer and was close to many of the blacklisted figures in midcentury Hollywood. He left the studio in the later 1940s and set up a private business with his brother, making radio-communications devices for the military. He became very successful in the 1950s and ’60s. Monna studied harp and piano, and then when she was about fifty started painting in an abstract expressionist style. She was very progressive, went into psychoanalysis in the 1950s, and ...</p
I am not sure that I feel like singing, thanks very much for asking! Interview with Natalie Haynes
No full textIn her writings on ancient myth, the British author Natalie Haynes moves women to the centre of attention. Her two latest books, A Thousand Ships and Pandora’s Jar – a fiction novel and a non-fiction one – approach this topic from two different perspectives. This interview takes stock of Haynes’ motives and methodology as well as of the challenges she faces in the process of writing
FICTIONAL REPRESENTATION OF WOMEN SYMBOLIZING CONTEMPORARY VALUES IN SPECIAL REFERENCE TO NATALIE HAYNES “PANDORA’S JAR”
No full textThe present paper focuses on Fictional Representation of women symbolizing contemporary values in special reference to Natalie Haynes “Pandora’s Jar”. In Pandora's Jar: Ladies in the Greek Fantasies, Natalie Haynes, classicist, author, and telecaster, tries to reevaluate a portion of the persevering through impression of ladies from Greek fantasy. Haynes places ladies whose accounts have generally been kept to a great extent in the shadows, up front stage with her top to bottom investigation and reassessment of their heritages. In this book Haynes presents an open and provocative assortment of expositions, blending grant and a gnawing mind borne from her experience as a professional comic. Natalie Haynes picks ten ladies in Greek fantasies whose accounts have been told and retold, in artworks, containers, films, dramas, musicals. She saw that significant ladies characters in the first adaptations became nonexistent or pale shadows of themselves as time elapsed and with each retelling. The stores as told in the movies are the rendition that the vast majority see, recollect and accept. In this captivating book she retells the narrative of these ten Greek legendary ladies, dives into old texts and closer views them
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