185 research outputs found
Migration studies and chemical characterization of short chain cyclic polyester oligomers from food packaging laminate adhesives
No full textLaminates are extensively used for food packaging applications such as retort pouches and retort packaging, boil in the bag, microwavable packaging, military meals ready to eat (MRE’s), single serving dispensers, etc. Laminates are manufactured by bonding multiple layers of films together using adhesives, where each layer acts as a functional component and contributes to overall integrity of the package. Polyurethane adhesive, the most common choice of adhesive for flexible packaging, is the reaction product of polyurethane pre-polymer and/or diisocyanate with polyester. The polyester component reacts with isocyanate, forming urethane bonds and introduces soft chain segments into the final, cured polyurethane. During the formation of polyester, low molecular weight cyclic diesters and oligoesters are formed as unwanted byproducts. These low molecular weight species often migrate out of packaging into the contents of the package. Since these species are novel compounds, the safety and toxicological properties have not been investigated. Our research focused on studying the chemistry and migratory properties of these compounds. We conducted migration testing of laminates using USFDA recommended food simulants such as 10% Ethanol for aqueous and acid foods and 95% Ethanol for the fatty foods. Single side extraction cell assembly was used for the purpose of extraction which was conditioned at 100 °C for 30 min. In our research GC-MS analysis was used to determine chemical structures, gas chromatography retention time indices and the average migratory concentration levels of ten short chain cyclic diesters and oligoesters. The chemical structures were deduced by analyzing the characteristic fragmentation pattern. Also to investigate the predicted metabolic fate of short chain cyclic diesters and oligoesters after their ingestion and potential absorption into the bloodstream, they were treated with non-specific porcine esterase enzyme at 37 °C for 1 h. In our research it was also shown that the enzyme treatment metabolized the short chain cyclic diesters and oligoesters back into their original corresponding diol and dicarboxylic acid precursors.M.S.Includes bibliographical referencesby Aditi Shrikhand
Occupational Therapy Within an Intensive Comprehensive Aphasia Program: Outcomes for People Living With Chronic Stroke
No full textAbstract
Date Presented 4/1/2017
This poster presents findings from a study that supports inclusion of occupational therapy in an intensive, comprehensive aphasia program to increase performance of and satisfaction with valued occupations focusing on instrumental activities of daily living, leisure, work, and social participation for people with chronic stroke and aphasia.
Primary Author and Speaker: Anne Escher
Additional Authors and Speakers: Aditi Amlani, Angela Viani, Sue Berger</jats:p
Women in HPC Australasia, 3 years on
No full textThe Australasian Chapter of the global organisation Women in High Performance Computing (WHPC) began as a collaboration between New Zealand eScience Infrastructure, NCI Australia, Pawsey Supercomputing Research Centre, Monash University, and Australasian eResearch Organisations (AeRO). Launched in 2020, the Chapter (WHPC+ AusNZ)* is celebrating three years of hosting events and creating spaces where anyone interested in supporting diversity & inclusion in our HPC and eResearch communities can feel welcome, connect with others, and contribute to discussions and positive change. This lightning talk will share:an overview of the Chapter's purpose and objectiveshighlights from the last three years of activityways you can get involved We welcome anyone interested in learning more about the Chapter or who is keen to connect with others interested in supporting diversity & inclusion in HPC and eResearch.*Our Chapter has added a "+" to our name to encourage people from all walks of life, not just gender, to join and participate in our community.ABOUT THE AUTHOR(S)Based at the University of Auckland, Jana Makar coordinates communications and engagement strategies for New Zealand eScience Infrastructure (NeSI). She has a degree in Communications from the University of Calgary and spent the early part of her career working as a newspaper journalist.Based at the Pawsey Supercomputing Centre, Aditi Subramanya is a communicator in the digital world. Aditi loves tech and is passionate about creating diverse, inclusive mindsets and cultures. Aditi’s goal is to break global barriers to create fair opportunities for all.For more information about eResearch NZ / eRangahau Aotearoa, visit:https://eresearchnz.co.nz/</p
Development of photochemical etching and its application in fabrication of integrated reflector metal semiconductor metal photodetectors
No full text"Photolithography and etching form the basis of any microfabrication process. Consequently, there is a lot of interest in the research community to improve and innovate on these crucial steps so as to realize the fabrication of complex devices. Once limited to use as physical photomasks for producing planar features, photolithography and etching are now being expanded to function with virtual programmable masks and to produce complex non-planar structures. These ""3-D"" structures are of great interest in fields like photonics, microfluidics and microelectromechanical systems (MEMS). A number of competitive solutions have been proposed to enable this ""grayscale"" processing of materials.
This thesis discusses digital projection photochemical etching as a possible tool for maskless, grayscale lithography and etching in a single step. It is based on light-assisted etching of semiconductors placed in a suitable chemical solution. By projecting spatially varying intensity light, grayscale etching can be achieved. The thesis begins with the motivation and literature review of this area of study, and then discusses the fundamental mechanisms of the photochemical etching process. Finally, an application of the fabrication of high-responsivity metal-semiconductor-metal (MSM) photodetectors is discussed to show how photochemical etching can be integrated with conventional microfabrication to enhance device fabrication capability."Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2019-05-01The student, Aditi Udupa, accepted the attached license on 2017-04-25 at 14:27.The student, Aditi Udupa, submitted this Thesis for approval on 2017-04-25 at 14:31.This Thesis was approved for publication on 2017-04-26 at 12:16.DSpace SAF Submission Ingestion Package generated from Vireo submission #11051 on 2017-08-10 at 15:07:00Made available in DSpace on 2017-08-10T20:33:24Z (GMT). No. of bitstreams: 2
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Previous issue date: 2017-04-26Embargo set by: Colleen Fallaw for item 102835
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Editing by leucyl-trna synthetase: Discrimination of norvaline and isoleucine
No full textAminoacyl tRNA-synthetases (AARS) are housekeeping enzymes that are tasked with accurate synthesis of aminoacylated tRNA for protein synthesis and other cellular functions. The specificity of amino acid attachment challenges the AARSs that need to distinguish between structurally similar amino acids. In such cases, AARSs have developed editing mechanisms to circumvent the issue of misaminoacylation.
Leucyl-tRNA synthetase (LeuRS), for instance selectively edits misactivated and mischarged non-leucine amino acids via pre-transfer editing of misactivated adenylates in the synthetic site or by hydrolyzing mischarged amino acids in the CP1 editing domain. The enzyme’s dependence between the two editing mechanisms can shift based on the origin from which the AARS is derived, the amino acid that is targeted for editing, or presence of a mutation in the enzyme. In the absence of the CP1 domain, E. coli LeuRS (LeuRS-ΔCP1) maintains fidelity by clearing non-leucine aminoacyl-adenylates in the enzyme’s synthetic site. The intact tRNA 3’-terminal adenosine (A76) residue is a prerequisite for aminoacylation.
Leveraging A76 essentiality tRNA analogues were designed to investigate amino acid dependent specificity of editing by LeuRS. The tRNA analogues were synthesized by addition of a modified adenosine triphosphate to an in vitro transcribed E. coli tRNALeuUAA using the CCA-adding enzyme from E. coli. Incorporation of unchargeable tRNA analogues stimulated ATP hydrolysis by wild type LeuRS in the presence of norvaline. In contrast, pre-transfer editing occurs independent of the tRNA for LeuRS-ΔCP1, which lacks the CP1 domain. Therefore it is hypothesized that the CP1 domain of LeuRS plays a critical role for tRNA-dependent pre-transfer editing.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2020-12-01The student, Aditi Banerjee, accepted the attached license on 2018-12-04 at 09:13.The student, Aditi Banerjee, submitted this Dissertation for approval on 2018-12-04 at 09:24.This Dissertation was approved for publication on 2018-12-05 at 08:43.DSpace SAF Submission Ingestion Package generated from Vireo submission #13192 on 2019-02-07 at 14:18:57Made available in DSpace on 2019-02-07T20:44:09Z (GMT). No. of bitstreams: 3
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Previous issue date: 2018-12-05Embargo set by: Seth Robbins for item 109858
Lift date: 2021-02-07T20:44:35Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Only Restriction Lifted for Item 109858 on 2021-02-08T10:15:29Z
Automated profile builder: one stop portal for creating and sharing your personal profiles
No full textThe explosive growth in digital presence have changed the way people form and stay connected to their professional networks, leading to the rise in multiple online profile management tools each catering to custom profile generation needs. With digital presence being split across multiple online tools, the challenge to maintain, update and customize details of all online profiles has been a challenge, perhaps more so in the academic researcher and professional community where a long list of publication and multiple pages of online profile is the norm. Today a typical researcher can have profiles that range from 1-2 pages like the typical industry standard to several pages as per typical academic standards where publications, patents, talks, workshops, etc are all part of a researchers profile. Maintaining this profile online across various independently run profile management system has created the problem of tedious multiple locations of data managements. As no existing profile management system leverages data from other systems it has been difficult for researchers to maintain and update online profiles. In addition, most of the profile management system have a fixed schema while creating online profile so the user does not have the flexibility to create a customized profile. In this thesis, we propose an Automated Profile Builder(AutoPB) which acts as a one stop portal for all the online profile management system. AutoPB aims to solve the issues surrounding current distributed and scattered profile management systems by its three main features: a) schema sharing, b) centralized multi format data in/out portal and c) client-side data retrieval system. First concept is known as schema sharing, which is a unique feature that no other profile management system has. This feature lets user to learn and share schema that are used while building an online profile. Secondly, the system provides flexible Import and Export feature. The user can import data from external sources as well as export the profile in different formats. Lastly, the profile builder performs client-side searching, crawling and parsing to minimize the server work load. Using our profile builder users can import data from their existing online profile and would not need to manually type their information which is easily available in the internet. In this thesis, we demonstrate that AutoPB with these features can act as a one stop portal especially for researchers to more easily manage their online profile by centralized data management paired with distribution of multiple custom profiles.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2019-08-01The student, Aditi Adhikari, accepted the attached license on 2017-07-12 at 00:56.The student, Aditi Adhikari, submitted this Thesis for approval on 2017-07-12 at 01:22.This Thesis was approved for publication on 2017-07-12 at 16:45.DSpace SAF Submission Ingestion Package generated from Vireo submission #11418 on 2017-09-29 at 11:19:05Made available in DSpace on 2017-09-29T16:39:46Z (GMT). No. of bitstreams: 2
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Lift date: 2019-09-29T17:52:45Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 103428 on 2019-09-30T09:15:20Z
Methodology and applications of topology optimization in nanophotonics
No full textAs photonic integrated circuits are becoming more diverse in functionality and compact in size, the traditional design approach based on physical intuition becomes limited. There is a great interest in the research and development of inverse design for nanophotonics as it can surpass the limitations of brute-force design by intuition and few-parameter sweeps. We studied the inverse design approach to photonic device design, and this dissertation presents our work in advancing current topology optimization approaches for nanophotonics and applying it to several versatile applications.
We discuss the extension of conventional topology optimization both from a methodology perspective as well as an application perspective. From a methodology perspective, we develop an approach to generalize topology optimization to include grayscale structures and discrete-height structures, which expands the design space. We apply this broader form of topology optimization to different cases both in integrated photonics to design ultra-compact power splitters and polarization splitters, and in free-space optics to design chiro-optic devices. We also extend inverse design to heterogeneous photonic integration for a compact edge-coupler for coupling the light from an edge-emitting transistor laser to a passive waveguide. This study demonstrates that for complex device architectures with multiple materials and constraints, inverse design can alleviate the load on the designer. We designed an ultra-compact spot-size converter with misalignment tolerances within the margin of the proposed fabrication tools. We also developed designs for an ultra-compact ring resonator by utilizing conventional topology optimization but applied in a unique way. By optimizing only the 90-degree bend and cascading it to form a ring, the physics and interpretability of the device are maintained. Finally, we discuss our efforts to develop an open-source, cluster-deployable inverse design code so that topology optimization can be done for large devices.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2022-08-01The student, Aditi Udupa, accepted the attached license on 2020-07-16 at 12:09.The student, Aditi Udupa, submitted this Dissertation for approval on 2020-07-16 at 12:49.This Dissertation was approved for publication on 2020-07-16 at 13:49.DSpace SAF Submission Ingestion Package generated from Vireo submission #15654 on 2020-10-02 at 15:51:12Made available in DSpace on 2020-10-07T22:50:02Z (GMT). No. of bitstreams: 3
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Previous issue date: 2020-07-16Embargo set by: Seth Robbins for item 116342
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Adaptation to climate change: a comparative analysis of modelling methods for heat-related mortality
No full textBackground: Multiple methods are employed for modelling adaptation when projecting the impact of climate change on heat-related mortality. The sensitivity of impacts to each is unknown because they have never been systematically compared. In addition, little is known on the relative sensitivity of impacts to “adaptation uncertainty” (i.e. the inclusion/exclusion of adaptation modelling), relative to using multiple climate models and emissions scenarios.
Objectives: (1) Compare the range in projected impacts that arises from using different adaptation modelling methods; (2) compare the range in impacts that arises from adaptation uncertainty to ranges from using multiple climate models and emissions scenarios; (3) recommend modelling method(s) to use in future impact assessments.
Methods: We estimated impacts for 2070-2099, for 14 European cities, applying six different methods for modelling adaptation; also with climate projections from five climate models, run under two emissions scenarios to explore the relative effects of climate modelling and emissions uncertainty.
Results: The range of the difference (%) in impacts between including and excluding adaptation, irrespective of climate modelling and emissions uncertainty, can be as low as 28% with one method and up to 103% with another (mean across 14 cities). In 13 of 14 cities the ranges in projected impacts due to adaptation uncertainty are larger than those associated with climate modelling and emissions uncertainty.
Conclusions: Researchers should carefully consider how to model adaptation because it is a source of uncertainty that can be greater than the uncertainty in emissions and climate modelling. We recommend absolute threshold shifts and reductions in slope
Electric-field-assisted swirl-flame synthesis of high-porosity nanostructured titania (TiO2) films
No full textNanostructured mesoporous metal-oxide films can be used in various applications, including dye-sensitized solar cells based on titania. Optimization of the properties of these films is crucial in improving their efficiency. Nanostructured TiO2 films with high uniformity and porosity are grown in a stagnation swirl flame setup under an applied electric field. The effects of external electric-field magnitude and polarity are studied for different substrate temperatures and precursor loading concentrations. The results show considerable differences in film characteristics, for differing electric fields, with more columnar structures and higher porosities under low voltages up to ±400 V. The films have higher packing density at higher voltages of ±800 V. At low substrate temperatures, the morphology and structure are more prominent owing to less on-substrate sintering of the nanoparticles. At low voltages, oppositely-charged particles will be attracted to the substrate increasing the electrophoretic velocity but decreasing the in-flame agglomeration; while at high voltages, the particles will be repelled and stay in the flame longer, thus increasing the in-flame agglomeration. A simple model is proposed which predicts the trend for deposition of particles and formation of nanostructured TiO2 films of a given morphology by balancing the effects of thermophoresis, electrophoresis, and Brownian motion of the particles. The model’s trend for packing density agrees with the experiments.M.S.Includes bibliographical referencesby Aditi Kulkarn
Free to learn: why unleashing the instinct to play will make our children happier, more self-reliant, and better students for life
No full textPeter Grays Free to learn is a powerful and interesting exploration of the biological underpinnings of education. Inspired by his own young sons rebellion against schooling, here he sets out to prove that schools destroy the natural instinct to learn. Whether one agrees with him on the evils of the present education system or vigorously disagrees that the current system fails our students utterly on every level, this is a thought-provoking read for not only evolutionary biologists, but also psychologists, citizens, policy-makers, and especially for parents and teachers. KEYWORDS: Free to lear
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