A free radical synthesis of Y-lactones using tri-n-butylstannyl iodoesters

Interest in the use of free radical reactions in synthetic organic chemistry has greatly intensified in recent years. A program was undertaken to develop a free radical synthesis of (gamma)-lactones which would occur under neutral conditions. Thus, treatment of olefins with tri-n-butylstannyl iodoacetate in the presence of a catalytic amount of the free radical initiator, 2,2\u27-azobis(2-methylpropionitrile) (AIBN) in refluxing benzene resulted in good yields of 4-substituted-(gamma)-lactones. The products were separated from iodotri-n-butylstannane by partitioning between acetonitrile and hexanes. Further purification by column chromatography afforded the pure (gamma)-lactones;This reaction has also been extended to the synthesis of bicyclic lactones via the intramolecular cyclizations of appropriately constructed tri-n-butylstannyl iodoesters under the same reaction conditions. The mild reaction conditions employed allow for the introduction of a variety of functional groups at the 4-position including alcohols, ethers, and even alkylsilanes and silyl ethers

Secondary production, trophic position, and potential for accumulation of polycyclic aromatic hydrocarbons in predatory Diptera in four wetlands of the Athabasca oil sands, Alberta, Canada.

Larvae of aquatic Diptera are important predators in fishless wetlands of northeast Alberta. Annual production was estimated for benthic (Chironomidae: Tanypodinae) and pelagic (Chaoboridae: Chaoborus) dipteran populations in 4 wetlands in surface-mined areas of the Athabasca oil sands, two of which received oil sands mine process material (OSPM; containing polycyclic aromatic hydrocarbons (PAHs)), and two of which were reference wetlands. The structure of benthic and pelagic food webs was estimated by measuring stable carbon and nitrogen isotopes. Stable nitrogen isotopes were also used to determine trophic levels of Tanypodinae and Chaoborus in order to determine their potential to bioaccumulate PAHs. Annual production was estimated along with total PAH body burdens to determine the potential for biomass and PAH export by the emergent adult insects. Tanypodinae production (1.55--28.77 g/m2/y) consistently exceeded Chaoborus production (0.009--0.372 g/m 2/y). Chaoborus trophic position estimates were consistently greater than estimates for Tanypodinae, suggesting greater PAH bioaccumulation potential for Chaoborus. Tanypodinae had greater potential to export PAHs (1.86--37.1 mg/m 2/y) than Chaoborus (1.1 x 10-2 --4.5 x 10-1 mg/m2/y) due to greater production and PAH body burdens. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2002 .G36. Source: Masters Abstracts International, Volume: 41-04, page: 1006. Adviser: Jan J. H. Ciborowski. Thesis (M.Sc.)--University of Windsor (Canada), 2002

Drawing on Gifts of International Students to Develop International Partnerships

It was Tuesday of the first week of classes for the fall 2012 term. At two o’clock in the afternoon, swamped with student petitions to register for classes and balancing myriad administrative issues, I found a young man with an unfamiliar accent standing on my office threshold. “I don’t have an appointment, but might you have a moment? My name is Carl. This is my second day in the states from Norway, and I heard about the honors program and would like to join.” A few days exist in an educator’s life that one can consider change moments, and that particular Tuesday proved to be one for me. Carl, a sophomore transfer student from the American College of Norway, demonstrated the rare confidence to reach out, and in doing so he has transformed honors education at our institution. Carl has served as an invaluable catalyst for our honors college to form an unprecedented relationship with the Norwegian Nobel Institute (NNI). The NNI supports the five-member panel that comprises the Nobel Committee and annually awards the Nobel Peace Prize. The possibilities of this relationship are only now coming to fruition: in the words of poet Robert Browning, “The best is yet to be . . .” (“Rabbi ben Ezra” 2). Extraordinary experiences unfold in Carl’s story, but it also provides honors directors with sage advice: drawing from the gifts of international students and inviting them into the honors community can play a dramatic role in internationalizing honors. Carl’s exemplary involvement provided intercultural understanding and an appreciation of global citizenship among students in our honors college and the larger campus community. His participation triggered a progression of events that ultimately created an institutional partnership with the NNI. The support that enabled Carl to acclimate into honors education and the strategies we collaboratively used to build an international partnership are arguably replicable on any campus. Carl’s story suggests how other institutions might maximize unique opportunities for engagement with their own international student population. Before explaining Carl’s contributions, this essay contextualizes the possibilities of engaging international students by reviewing the current statistics regarding international students in the United States

Local measurements of cyclotron states in graphene

Multilayer epitaxial graphene has been shown to contain "massless Dirac fermions" and is believed to provide a possible route to industrial-scale graphene electronics. We used scanning tunneling microscopy (STM) and spectroscopy (STS) in high magnetic fields to obtain local information on these fermions. A new STS technique was developed to directly measure graphene's energy-momentum relationship and resulted in the highest precision measurement of graphene's Dirac cone. STS spectra similar to ideal graphene were observed, but additional anomalies were also found. Extra peaks and an asymmetry between electron and hole states were shown to be caused by the work function difference between the Iridium STM tip and graphene. This tip effect was extracted using modeled potentials and performing a least square fit using degenerate perturbation theory on graphene's eigenstates solved in the symmetric gauge. Defects on graphene were then investigated and magnetic field effects were shown to be due to a mixture of potential effect from defects and the tip potential. New defect states were observed to localize around specific defects, and are believed to interact with the STM tip by Stark shifting in energy. This Stark shift gives a direct measurement of the capacitive coupling between the tip and graphene and agrees with the modeled results found when extracting the tip potential.Ph.D.Committee Chair: First, Phillip; Committee Member: Jiang, Zhigang; Committee Member: Kindermann, Markus; Committee Member: Stroscio, Joseph,; Committee Member: Zangwill, Andre

Al-Ce-Mn Solidification Phase Selection and Solid-State Phase Transformations

The design of Al alloys has become an important topic in Additive Manufacturing (AM). The adoption of Al alloys to AM has been difficult because traditional alloys are prone to processing related defects such as solidification cracking. The Al-10Si-Mg alloy was initially adopted because of its resistance to solidification cracking. However, the Al-10Si-Mg alloy has reduced tensile properties especially at high temperatures, where the silicon phase coarsens readily. Therefore, efforts have been made to design new Al alloys that can take advantage of the AM processing. The goal of new alloys is to optimize based on rapid solidification conditions, while being less prone to processing related defects. The Al-Ce, and higher order Al-Ce-X, systems have been adopted because of the low solubility and diffusivity of Ce through FCC Al. The challenge is metastable phases form as a function of the unique processing conditions. Metastable phases have been observed to have unique phase transformations during heat treatment. The goal is to understand the above observations. In this work, an Al-10Ce-8Mn (wt.%) alloy is used to understand the metastable phase Al20Mn2Ce. The Al20Mn2Ce phase, surrounded by FCC Al has different decomposition pathways (at 400 C) depending on its thermal history within a single weld track. Initially, the research focuses on an AM Al-Ce-Mn part that demonstrates the change in decomposition pathways based upon the local solidification conditions, e.g., primary Al20Mn2Ce to eutectic (between FCC Al and Al20Mn2Ce) solidification. Following the AM parts, weld tracks are preformed to understand the role of solidification conditions that can lead to each decomposition pathway observed in the Al-Ce-Mn system. The interface response function model is used to understand phase selection as a function of solidification conditions. The overall goal of this work is to demonstrate how a single metastable phase in a weld track, specifically Al20Mn2Ce, may be manipulated by local solidification conditions, and how that affects the subsequent phase decomposition. The impact of this work is to understand the role of solidification conditions on the solid-state phase transformation to give insight into how the mechanical properties of a particular alloy can be controlled

Using AI to Analyze Patent Claim Indefiniteness

We describe how to use artificial intelligence (AI) techniques to partially automate a type of legal analysis, determining whether a patent claim satisfies the definiteness requirement. Although fully automating such a high-level cognitive task is well beyond state-of-the-art AI, we show that AI can nevertheless assist the decision maker in making this determination. Specifically, the use of custom AI technology can aid the decision maker by (1) mining patent text to rapidly bring relevant information to the decision maker’s attention, and (2) suggesting simple inferences that can be drawn from that information. We begin by summarizing the law related to patent claim indefiniteness. A summary of existing case law allows us to identify the types of information that can be relevant to the legal determination of indefiniteness. This in turn guides us in designing AI software that processes a patent’s text to extract information that can be relevant to the legal analysis of indefiniteness. Some types of relevant information include whether terms in a claim are defined in the patent, whether terms in a claim are not mentioned in the patent’s specification, whether the claim includes non-standard terms coined by the drafter of the patent, whether the claim relies on vaguely-specified measurements, and whether the patent’s specification discloses structure corresponding to a means-plus-function limitation. The AI software rapidly processes a patent’s text and identifies information that is relevant to the legal analysis. The software then provides the human decision maker with this information as well as simple metrics and inferences, such as the percentage of claim terms that are defined explicitly or by example, and whether terms that are coined by the drafter should be defined or renamed. This can provide the user with insights about a patent much faster than if the user read the entirety of the patent to locate the same information unaided. Moreover, the software can aggregate the various types of information to “score” a claim (e.g., from 0 to 100) based on its risk of being deemed indefinite. For example, a claim containing only defined terms and lacking any vague measurements would score much lower in terms of risk than a claim with terms that are not only undefined but do not even appear in the patent’s specification. Once each claim in a patent is assigned such an indefiniteness score, the patent itself can be given an overall indefiniteness score. Scoring groups of patents in this manner has further advantages even if the scores are blunt measurements. AI software ranks a group of patents (e.g., all patents owned by a company) by indefiniteness scores. This allows a very large set of patents to be quickly searched for patents that have the highest, or lowest, indefiniteness score. The results of such a search could be, e.g., the patents to target for detailed review in litigation, post-grant proceedings, or licensing negotiations. Finally, we present some considerations for refining and augmenting the proposed methods for partially automating the indefiniteness analysis, and more broadly other types of legal analysis

How Profitable are Equity Release Mortgages?

We obtain valuations of UK Equity Release Mortgages under the ‘market consistent’ approach consistent with conventional option pricing and the ‘discounted projection’ approach used by the industry. Projections of the expected profitability of these products have significant commercial implications

Programming Idioms for Transactional Events

Transactional events (TE) are an extension of Concurrent ML (CML), a programming model for synchronous message-passing. Prior work has focused on TE's formal semantics and its implementation. This paper considers programming idioms, particularly those that vary unexpectedly from the corresponding CML idioms. First, we solve a subtle problem with client-server protocols in TE. Second, we argue that CML's wrap and guard primitives do not translate well to TE, and we suggest useful workarounds. Finally, we discuss how to rewrite CML protocols that use abort actions