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Title: Michigan potato research report. Vol. 52 (2020)
Date: 2021
Collection: Michigan Potato Research Reports

Title: Gressforum. No. 2021:1
Date: 2021
Collection: Gressforum

Title: RESPONSE OF ULTRA HIGH PERFORMANCE FIBER REINFORCED CONCRETE BEAMS UNDER FLEXURE AND SHEAR
Creator: Solhmirzaei, Roya
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Ultra high performance concrete (UHPC) is an advanced cementitious material made with low water to binder ratio and high fineness admixtures, and possesses a unique combination of superior strength, durability, corrosion resistance, and impact resistance. However, increased strength of UHPC results in a brittle behavior. To overcome this brittle behavior of UHPC and improve post cracking response of UHPC, steel fibers are often added to UHPC and this concrete type is designated as Ultra High...
Show moreUltra high performance concrete (UHPC) is an advanced cementitious material made with low water to binder ratio and high fineness admixtures, and possesses a unique combination of superior strength, durability, corrosion resistance, and impact resistance. However, increased strength of UHPC results in a brittle behavior. To overcome this brittle behavior of UHPC and improve post cracking response of UHPC, steel fibers are often added to UHPC and this concrete type is designated as Ultra High Performance Fiber Reinforced Concrete (UHPFRC). Being a relatively new construction material, there are limited guidelines and specifications in standards and codes for the design of structural members fabricated using UHPFRC. To develop a deeper understanding on the behavior of UHPFRC flexural members, seven beams made of UHPFRC are tested under different loading conditions. The test variables include level of longitudinal reinforcement, type of loading (shear and flexure), and presence of shear reinforcement. Further, a finite element based numerical model for tracing structural behavior of UHPFRC beams is developed in ABAQUS. The developed model can account for the nonlinear material response of UHPFRC and steel reinforcement in both tension and compression, as well as bond between concrete and reinforcing steel, and can trace the detailed response of the beams in the entire range of loading. This model is validated by comparing predicted response parameters including load-deflection, load-strain, and crack propagation against experimental data obtained from tests on UHPFRC beams with different material characteristics and under different loading configurations. The validated model is applied to conduct a set of parametric studies to quantify the effect of different parameters on structural response of UHPFRC beams, including the contribution of stirrups and concrete to shear capacity of beams, to explore feasibility of removing the need for shear reinforcement in UHPFRC beams. Results from experiments and numerical model reveal that UHPFRC beams exhibit distinct cracking pattern characterized by the propagation of multiple micro cracks followed by widening of a single crack leading to failure. Also, UHPFRC beams exhibit high flexural and shear capacity, as well as ductility due to high compressive and tensile strength of UHPFRC and fiber bridging developing at the crack surfaces that leads to strain hardening in UHPFRC after cracking. Thus, absence of shear reinforcement in UHPFRC beams does not result in brittle failure, even under dominant shear loading. Data from the conducted experiments as well as those reported in literature is utilized to develop a machine learning (ML) framework for predicting structural response of UHPFRC beams. On this basis, a comprehensive database on reported tests on UHPFRC beams with different geometric, fiber properties, loading and material characteristics is collected. This database is then analyzed utilizing different ML algorithms, including support vector machine, artificial neural networks, k-nearest neighbor, support vector machine regression, and genetic programing, to develop a data-driven computational framework for predicting failure mode and flexural and shear capacity of UHPFRC beams. Predictions obtained from the proposed framework are compared against the values obtained from design equations in codes, and also results from full-scale tests to demonstrate the reliability of the proposed approach. The results clearly indicate that the proposed ML framework can effectively predict failure mode and flexural and shear capacity of UHPFRC beams with varying reinforcement detailing and configurations. The research presented in this dissertation contributes to the development of preliminary guidance on evaluating capacity of UHPFRC beams under different configurations.
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Title: YOUTH PERSPECTIVES ON FULL-SERVICE COMMUNITY SCHOOLING
Creator: Castro, Kristofer Malulani
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Despite the national standards for the implementation of full-service community schooling require the inclusion of youth participation in the decision-making and communication of these initiatives, few studies have solicited these key perspectives. The current study used focus groups to solicit youth perspectives on full-service community schooling initiatives being implemented in the schools they attended. Students were recruited from schools participating in the early years of a full...
Show moreDespite the national standards for the implementation of full-service community schooling require the inclusion of youth participation in the decision-making and communication of these initiatives, few studies have solicited these key perspectives. The current study used focus groups to solicit youth perspectives on full-service community schooling initiatives being implemented in the schools they attended. Students were recruited from schools participating in the early years of a full-service community schooling initiative. Students were separated into focus groups based on the school they were recruited from. The questions I sought to answer through this study were: 1.) what does full-service community schooling mean to students; 2.) what characteristics of full-service community schooling do youth enjoy (and not enjoy); 3.) how, if at all, has full-service community schooling changed the lives of youth; and 4.) what factors salient to youth does full-service community schooling fail to address? Analyzing the transcripts from the focus group using Marshall and Rossman’s (1995) interrater qualitative approach produced 35 themes grouped into ten analytical categories that were then further reduced into four higher order content groupings. I discuss the manner in which these findings elucidate how youth understand the scope, benefits, and issues with full-service community schooling. Furthermore, I discuss, the implications of these findings for the future practice of and research on youth voice in the planning and design of full-service community schooling.
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Title: “IMFUNDO” THE STUDENT; THE EVOLUTION ADAPTATION, AND PRACTICE OF African CENTERED EDUCATION AT THE KARA HERITAGE INSTITUTE IN PRETORIA SOUTH AFRICA
Creator: George III, Clarence
Date: 2021
Collection: Electronic Theses & Dissertations
Description: ABSTRACT“IMFUNDO” THE STUDENT; THE EVOLUTION ADAPTATION, AND PRACTICE OF AFRICAN CENTERED EDUCATION AT THE KARA HERITAGE INSTITUTE IN PRETORIA SOUTH AFRICAByClarence George III This dissertation study (Imfundo) seeks to explore, the practice and evolution of African centered education at the Kara Heritage Institute from 2016 to 2019. This project seeks to study African centered education at Kara focusing on how the Heritage Institute instills notions of African consciousness, notions of Pan...
Show moreABSTRACT“IMFUNDO” THE STUDENT; THE EVOLUTION ADAPTATION, AND PRACTICE OF AFRICAN CENTERED EDUCATION AT THE KARA HERITAGE INSTITUTE IN PRETORIA SOUTH AFRICAByClarence George III This dissertation study (Imfundo) seeks to explore, the practice and evolution of African centered education at the Kara Heritage Institute from 2016 to 2019. This project seeks to study African centered education at Kara focusing on how the Heritage Institute instills notions of African consciousness, notions of Pan-Africanism, structural pedagogy, and culturally relevant pedagogy. This research project evaluated and observed African-centered education in South Africa at the Kara Heritage institute in Pretoria South Africa. Over 4 years of data collected has yielded a great deal of information about South Africa's unique approach to education, culture, and heritage restoration.
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Title: The necessary and sufficient conditions in weighted inequalities for singular integrals and a local Tb theorem with an energy side condition.
Creator: Grigoriadis, Christos
Date: 2021
Collection: Electronic Theses & Dissertations
Description: We provide an essentially complete dictionary of all implications among the basic and fundamental conditions in weighted theory such as the doubling, one weight $A_p(w)$, $A_\infty$ and $C_p$ conditions as well as the two weight $\A_p(\o,\s)$ and the ``buffer" Energy and Pivotal conditions. The most notable implication is that in the case of $A_\infty$ weights the two weight $\A_p$ condition implies the $p-$Pivotal condition hence giving an elegant and short proof of the known NTV-conjecture...
Show moreWe provide an essentially complete dictionary of all implications among the basic and fundamental conditions in weighted theory such as the doubling, one weight $A_p(w)$, $A_\infty$ and $C_p$ conditions as well as the two weight $\A_p(\o,\s)$ and the ``buffer" Energy and Pivotal conditions. The most notable implication is that in the case of $A_\infty$ weights the two weight $\A_p$ condition implies the $p-$Pivotal condition hence giving an elegant and short proof of the known NTV-conjecture with $p=2$ for $A_\infty$ weights in terms of existing T1 theory. We also provide a quite technical construction inspired by \cite{GaKS} proving that we can have doubling weights satisfying the $C_p$ condition which are not in $A_\infty$. We obtain a local two weight $Tb$ theorem with an energy side condition for higher dimensional fractional Calder\'{o}n-Zygmund operators. The proof follows the general outline of the proof for the corresponding one-dimensional $Tb$ theorem in \cite{SaShUr12}, but encountering a number of new challenges, including several arising from the failure in higher dimensions of T. Hyt\"{o}nen's one-dimensional two weight $A_{2}$ inequality. Hyt\"{o}nen used this inequality to deal with estimates for measures living in adjacent intervals. Hyt\"{o}nen's theorem states that the off-testing condition for the Hilbert transform is controlled by the Muckenhoupt's $A_2$ and $A^*_2$ conditions. So in attempting to extend the two weight $T_b$ theorem to higher dimensions, it is natural to ask if a higher dimensional analogue of Hyt\"{o}nen's theorem holds that permits analogous control of terms involving measures that live on adjacent cubes.We show that it is not the case even in the presence of the energy conditions used in one dimension \cite{SaShUr12}. Thus, in order to obtain a local $T_b$ theorem in higher dimensions, it was necessary to find some substantially new arguments to control the notoriously difficult nearby form. More precisely, we show that Hyt\"{o}nen's off-testing condition for the two weight fractional integral and the Riesz transform inequalities is not controlled by Muckenhoupt's $A_2^\alpha$ and $A_2^{\alpha,*}$ conditions and energy conditions.
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Title: High Functional Density Through Rigid-Flex
Creator: Gjokaj, Vincens
Date: 2021
Collection: Electronic Theses & Dissertations
Description: In the last decade Additive Manufacturing (AM), often referred to as 3D printing, has garnered signficant interest in systems packaging. It has proven as an effective way of producing Radio Frequency (RF) to millimeter wave (mmWave) components and modules. AM enables flexible and rapid realization of structures with arbitrary shapes and complexity. AM is considered as one of the most important emerging material processing technologies that will drive the future designs of high functional...
Show moreIn the last decade Additive Manufacturing (AM), often referred to as 3D printing, has garnered signficant interest in systems packaging. It has proven as an effective way of producing Radio Frequency (RF) to millimeter wave (mmWave) components and modules. AM enables flexible and rapid realization of structures with arbitrary shapes and complexity. AM is considered as one of the most important emerging material processing technologies that will drive the future designs of high functional density modules and systems. This thesis investigates the us of AM for the design and fabrication of microwave and mmWave circuits and systems.Different AM technologies are used to design and demonstrate a range of high frequency passive and active components. Stereolithography printing is utilized to create passive components in the X-band (10-18 GHz) and K-band (18-27 GHz) frequency bands. These passive component designs are then combined with active RF circuits to design transmit and receive modules. Aerosol jet printing (AJP) is used to create an entirely printed mmWave components that avoids the use of traditional photolithography fabrication methods. All the designs are compared to their counterparts fabricated using conventional techniques. It is demonstrated that self-packaged RF components 3D form can readily be produced using AM leading to high functional density systems working well into the W-band frequency band.
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Title: POLYMERS AND POLYMER-CONJUGATES FOR CANCER IMMUNOTHERAPY : FOREIGN CYTOTOXIC T LYMPHOCYTE EPITOPE DELIVERY, CYTOTOXIC T LYMPHOCYTE ACTIVATION, AND NK92 CELL SURFACE ENGINEERING
Creator: Lang, Shuyao
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Cancer immunotherapy is considered as the fourth pillar of anti-cancer treatment, along with the traditional three pillars: surgery, radiotherapy, and chemotherapy. Polymers and polymer conjugates have been widely investigated as cancer immunotherapy carriers. The polymeric materials can not only prolong the circulation time of their small molecular cargoes, but also enhance immune activation via multiple mechanisms such as passively or actively targeting immune cells and specific tissue...
Show moreCancer immunotherapy is considered as the fourth pillar of anti-cancer treatment, along with the traditional three pillars: surgery, radiotherapy, and chemotherapy. Polymers and polymer conjugates have been widely investigated as cancer immunotherapy carriers. The polymeric materials can not only prolong the circulation time of their small molecular cargoes, but also enhance immune activation via multiple mechanisms such as passively or actively targeting immune cells and specific tissue environment. With their great flexibility of monomer selection and post-polymerization modification, polymers and polymer conjugates can satisfy the various needs for immunotherapy. In this dissertation, three different polymer/polymer conjugates have been investigated for facilitating different immunotherapy strategies.pH responsive acetalated dextran microparticles were (Ac-Dex MPs) investigated for the delivery of a high affinity foreign cytotoxic T lymphocyte (CTL) epitope, ovalbumin peptide (OVA), to tumor tissues. Successful OVA delivery to tumor tissue was observed. Both intratumorally and systematically administration of OVA encapsulated Ac-Dex MPs protected mice from pre-established “antigen-loss variant” tumor models. Ultra-pH sensitive nanoparticles (NPs) based on methoxy poly(ethylene glycol)-b-[poly(diisopropylamino)ethyl methacrylate] have been synthesized as a platform for anti-cancer vaccine delivery. Representative CTL antigen OVA and adjuvant imiquimod (IMQ), were covalently conjugated to the polymer backbone through an acid responsive carboxy-dimethylmaleic amide linker (CDM) resulting in polymer P-CDM-OVA and P-CDM-IMQ, respectively. The P-CDM-OVA NPs greatly enhanced CTL responses in vivo compared to the free peptide or the previously reported Ac-Dex MPs encapsulating OVA. Co-administration of P-CDM-OVA NPs with P-CDM-IMQ NPs further improved CTL responses in vivo and effectively reduced tumor growth in mice. Besides serving as delivery carriers, polymers can also be used for surface engineering of immune cells. NK92 cells are a natural killer cell line which is highly cytotoxic, but lack of inherent selectivity toward cancer. We investigated the surface engineering of NK92 with two different strategies: metabolic glycoengineering, and hydrophobic insertion of a polymer grafted with multiple copies of trisaccharide CD22 ligands and a cholesterol terminal. Both methods can successfully modify the surface of NK92 with CD22 ligand and enhance the specific lysis of CD22+ cell lines in vitro. Further investigation of metabolic glycoengineering method showed significant protection against CD22+ tumor in vivo.
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Title: TWO WEIGHTED CARLESON EMBEDDINGS ON MULTI-TREES AND MULTI-DISK
Creator: Psaromiligkos, Georgios
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Given two measures μ,w on a multi-tree T^n we prove a two weighted multi-parameterdyadic embedding theorem for the Hardy operator, assuming w is a product weight and a certain “Box” condition holds. The main result has been long proven for dimension n = 1, however, for higher dimensions the result was not known. There was a general feeling such an embedding was not possible under the Box condition, due to a famous counterexample by Lennart Carleson. In this counterexample, the measure μ was...
Show moreGiven two measures μ,w on a multi-tree T^n we prove a two weighted multi-parameterdyadic embedding theorem for the Hardy operator, assuming w is a product weight and a certain “Box” condition holds. The main result has been long proven for dimension n = 1, however, for higher dimensions the result was not known. There was a general feeling such an embedding was not possible under the Box condition, due to a famous counterexample by Lennart Carleson. In this counterexample, the measure μ was the two-dimensional Lebesgue measure, which is a product measure along with a non-product weight w. Shortly after, A. Chang imposed a (strictly) more general condition than the Box one and showed it is sufficient to get the same embedding in dimension n = 2. This was later used by A. Chang and R. Fefferman to characterize the dyadic n-dimensional product BMO, denoted by BMO_{prod}^d(R^n). Recently, the question of embedding the Dirichlet space on the bi-disk D^2 into L^2(D^2) appeared. This is equivalent to proving a general measure μ is “Carleson” for the Dirichlet space on D^2. It was shown that proving the (discrete) analogue of the embedding on a bi-tree is enough to get the same for the bi-disc. To do this, however, we need to change the restrictions on the measures; we will assume μ to be general and w to be a product weight. Given these restrictions, we managed to prove the surprising result that the Box condition is enough to imply the embedding for dimensions n = 2, 3. This is not contradictory to Carleson’s counterexample as the weight w was non-product.
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Title: WILDFIRE IMPACTS ON SOIL CARBON POOLS AND MICROBIAL COMMUNITIES IN MIXED-CONIFER FORESTS OF CALIFORNIA
Creator: Adkins, Jaron
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Forest ecosystems are important reservoirs for long term carbon (C) storage. Forests of the western United States account for 20-40% of total U.S. carbon C sequestration, and nearly half of the total C in these forests is stored in soil. However, many forests in the western U.S are experiencing wildfire conditions that diverge from historical fire regimes. Prior to Euro-American settlement, California’s mixed-conifer forests typically experienced frequent surface fires of low to moderate burn...
Show moreForest ecosystems are important reservoirs for long term carbon (C) storage. Forests of the western United States account for 20-40% of total U.S. carbon C sequestration, and nearly half of the total C in these forests is stored in soil. However, many forests in the western U.S are experiencing wildfire conditions that diverge from historical fire regimes. Prior to Euro-American settlement, California’s mixed-conifer forests typically experienced frequent surface fires of low to moderate burn severity, but, due to the combined effects of altered forest structure and climate change, now experience fires that are larger and more severe than historical conditions. Fires have numerous direct and indirect effects on the soil biological, chemical, and physical characteristics that influence the soil C cycle. Understanding how altered soil characteristics influence the cycling and persistence of soil C, and how they vary with severity, is important for managing forests for C storage and for predicting fire-climate feedbacks. My dissertation work incorporates observational and manipulative experiments to understand the direct and indirect effects of burn severity on soil C cycling and microbial communities over the short to intermediate term, with a particular focus on the distribution of soil C between active and slow cycling pools. Soil C can be conceptualized as discrete pools of variable persistence in soil. The active C pool is quickly decomposed, contributing to the return of CO2 to the atmosphere, whereas the non-active C pool is more stable and contributes to long term C storage. I leveraged a burn severity gradient resulting from a wildfire in a California mixed-conifer forest to determine the structure and kinetics of these C pools at an intermediate time point in post-fire recovery (i.e. three years). I found that the size of the non-active C pool was smaller in burned areas than unburned areas, and the kinetic rate of the non-active C pool was negatively related to burn severity. I also characterized the soil microbial communities across this severity gradient and identified the environmental characteristics responsible for differences. I found that fungal-to-bacterial ratio and oligotroph-to-copiotroph bacteria ratio decreased with burn severity, and these effects were driven by differences in live and dead tree basal area, soil nutrients, and pH. Leveraging another burn severity gradient, I then determined whether differences in microbial communities and soil C pools were related one-year post-fire in a mixed-conifer forest. I again found lower non-active C pool kinetic rates, and higher abundances of copiotrophic bacteria in burned compared to unburned areas. Differences in soil C pool kinetics were related to tree basal area, soil nutrients, and bacterial communities. I determined the short-term impacts of fire on soil C pools and cycling using lab experiments in which I manipulated soil heating intensity and pyrogenic organic matter (PyOM) additions. I found that high intensity soil heating can decrease microbial biomass C (MBC) accumulation, whereas PyOM had minimal effects on MBC in the short-term. Finally, I found that the size of the active C pool increased with soil heating intensity, while the kinetic rate of the non-active C pool decreased; PyOM primarily increased the size of the non-active C pool. Taken as a whole, my research suggests that fire induces short-term soil C losses by increasing the size of the active C pool, but, over the intermediate-term, residual soil C is more persistent. Fire severity is predicted to increase globally throughout the 21st century, and my research contributes to understanding how forest C storage will be affected by disrupted wildfire regimes.
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Title: Towards Proprioceptive Grasping With Soft Robotic Hands
Creator: da Silva Pinto, Thassyo
Date: 2021
Collection: Electronic Theses & Dissertations
Description: Various robotic hands, gloves, and grippers have been developed for manufacturing, prosthetics, and rehabilitation. However, the use of rigid links and joints presents challenges in control and safe interactions with humans. The emerging field of soft robotics seeks to create machines that are soft, compliant, and capable of withstanding damage, wear and high stress. This dissertation is focused on advancing soft actuators, soft sensors, and perception for ultimately realizing proprioceptive...
Show moreVarious robotic hands, gloves, and grippers have been developed for manufacturing, prosthetics, and rehabilitation. However, the use of rigid links and joints presents challenges in control and safe interactions with humans. The emerging field of soft robotics seeks to create machines that are soft, compliant, and capable of withstanding damage, wear and high stress. This dissertation is focused on advancing soft actuators, soft sensors, and perception for ultimately realizing proprioceptive grasping with soft robotic hands.In this work, several types of soft pneumatic actuators (SPAs) have been tested, fabricated, and tested, including one embedded with 3D-printed conductive polylactic acid (CPLA) layer capable of stiffness tuning and shape modulation. A gripper made of two soft actuators has been prototyped to demonstrate grasping of objects of different sizes and shapes, with desired posture-holding capabilities. Carbon nanotube (CNT)-based flexible sensor arrays have been designed, fabricated, and integrated to SPAs to provide distributed strain measurements. The presented approach allows customized design of stretchable sensor arrays with varied size and shape. Simulation and experimentation have been performed in order to analyze the soft actuator deformation during bending, and to confirm the capability of the integrated sensor array for capturing the actuator deformation. 3D printing of touch and pressure sensors has been further investigated for potential use in robotic hands. In particular, a novel process has been introduced for producing soft conductors and pressure sensors, involving first 3D-printing microchannels in soft substrates and then filling the channel with liquid metal. With a PolyJet printer, functional straight microchannels have been fabricated with sizes down to 150 x 150 micrometers in the cross-section area. In addition, spiral-shaped pressure sensors have been developed with a cross-section size of 350 x 350 micrometers and overall thickness of 1.5 mm (50A and 70A Shore Hardness). Although the sensors require a relatively large pressure threshold to operate, they have shown the ability to withstand high pressures up to 1 MPa and thus have potential to be used in industrial applications among others. Finally, preliminary computational exploration of intelligent grasping has been performed. In particular, the classification of soft grasped objects has been examined through a neuroevolution process for artificial brains. Simulation with SOFA (Simulation Open Framework Architecture) has been conducted to produce the emulated contact force measurements, which have been used to train artificial neural networks, including Markov Brains from the Modular Agent-Based Evolver (MABE) platform, to properly classify the shape and stiffness of the grasped objects.
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Title: Measurement of 34Ar(α,p)37K using the JENSA Gas Jet Target
Creator: Browne, Justin Edward
Date: 2021
Collection: Electronic Theses & Dissertations
Description: X-ray bursts are very luminous thermonuclear explosions that occur in binary star systems. In these systems, a neutron star accreting matter from a companion star undergoes a runaway thermonuclear explosion, caused by a breakout from the CNO-cycle into the αp-process. The αp-process consists of a series of (α,p) and (p,γ) reactions. In this process, there are “waiting point” nuclei at which the nuclear burning pauses until the stellar conditions change so that the (α,p) reaction rate...
Show moreX-ray bursts are very luminous thermonuclear explosions that occur in binary star systems. In these systems, a neutron star accreting matter from a companion star undergoes a runaway thermonuclear explosion, caused by a breakout from the CNO-cycle into the αp-process. The αp-process consists of a series of (α,p) and (p,γ) reactions. In this process, there are “waiting point” nuclei at which the nuclear burning pauses until the stellar conditions change so that the (α,p) reaction rate increases and burning continues. 34Ar is one of these waiting point nuclei, and sensitivity studies have found that varying the 34Ar(α,p)37K reaction rate significantly impacts the light curve of x-ray bursts.Because the 34Ar(α,p)37K cross section had never been directly measured before, the reaction rates used in simulations are based on Hauser-Feshbach predictions. These predictions are hypothesized to be inaccurate because the Hauser-Feshbach statistical model requires a high level density in the compound nucleus and assumes there are no dominant resonances.This thesis describes an experiment at the National Superconducting Cyclotron Laboratory (NSCL) designed to test Hauser-Feshbach predictions by directly measuring the 34Ar(α,p)37K cross section. A radioactive ion beam of 34Ar15+ with energies of 57.04 MeV and 54.19 MeV was delivered to a (5–8) × 10^18 atoms/cm^2 thick He target, created by the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target. The recoils and beam were detected by the ANASEN position-sensitive ionization chamber, and the ejectiles were detected by an array of silicon detectors combining SuperORRUBA and SIDAR. The beam included contamination from the decay products of 34Ar, namely 34Cl and 34S. While the contribution from 34S(α,p)37Cl could be subtracted because the cross section had be previously measured, the contributions from 34Cl(α,p)37Ar and 34Ar(α,p)37K could not be separated, so a combined cross section for the two was derived from the data.The combined 34Cl(α,p)37Ar and 34Ar(α,p)37K cross sections were determined to be (70 ± 21) mb at (5.91 ± 0.08) MeV and (52 ± 13) mb at (5.51 ± 0.08) MeV in the center of mass frame. Comparison with Hauser-Feshbach theory indicates that the experimental cross sections are lower by 37 % and 20 %, for the two energies, respectively. This suggests that the hypothesis that the Hauser-Feshbach model overestimates the 34Ar(α,p)37K cross section by 2 orders of magnitude is unlikely to be true at these energies.
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Title: Validation of the beta-Oslo Method; An Indirect Method for Constraining Neutron-Capture Cross Sections
Creator: Childers, Katherine Louise
Date: 2021
Collection: Electronic Theses & Dissertations
Description: One of the prevalent questions in nuclear science is the origin of the elements. There are two stellar nucleosynthesis processes considered to be responsible for the production of the majority of the abundances of the elements heavier than iron; the slow neutron-capture process (s-process) and the rapid neutron-capture process (r-process). Both of these processes are characterized by the successive capture of neutrons on nuclei, with the major differences between the processes being the...
Show moreOne of the prevalent questions in nuclear science is the origin of the elements. There are two stellar nucleosynthesis processes considered to be responsible for the production of the majority of the abundances of the elements heavier than iron; the slow neutron-capture process (s-process) and the rapid neutron-capture process (r-process). Both of these processes are characterized by the successive capture of neutrons on nuclei, with the major differences between the processes being the timescale over which the processes occur and the host environment. The s-process occurs in low neutron-density environments, such as low- to intermediate-mass stars, and proceeds slowly along the valley of stability. Since the nuclei involved are close to stability, the reactions involved are amenable to direct measurements. The r-process progresses through an explosive event with high neutron densities which drives material far from stability. The recent observation of a neutron star merger event by LIGO and Virgo and the subsequent electromagnetic follow up has demonstrated that an r-process event can occur in these rare events, but it has not ruled out other potential astrophysical sites. To better understand and model the r-process, several nuclear properties are needed for a large number of nuclei, including neutron-capture cross sections. R-process nuclei are not viable for direct measurement of neutron-capture cross sections since the nuclei involved are far from stability, and thus have short half-lives. Therefore, several indirect measurement techniques have been developed to provide experimental constraints on neutron-capture cross sections. One such method is the beta-Oslo method, which uses beta decay to populate highly excited states of a nucleus. The resulting de-excitation via the emission of gamma rays is used to extract statistical nuclear properties of the daughter nucleus. These properties are then used as input in a reaction model to constrain the neutron-capture cross section. The beta-Oslo method can provide a large number of constrained neutron-capture cross sections far from stability, but it is necessary to validate the method using a direct neutron capture measurement. This work will present a validation of the beta-Oslo method in the A = 80 mass region with the 82Se(n, gamma)83Se reaction. The nuclide 83Se can be accessed through the beta-decay of 83As, which was studied at the National Superconducting Cyclotron Laboratory with the total absorption spectrometer, SuN. Using the beta-Oslo method, the cross section of the 82Se(n, gamma)83Se reaction was constrained. A direct measurement of the 82Se(n, gamma)83Se reaction was performed with the Detector for Advanced Neutron Capture Experiments and the cross section obtained from the direct measurement is compared to the cross section determined using the beta-Oslo method. The results are in good agreement, validating the beta-Oslo method as a viable method for constraining neutron-capture cross sections.
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Title: The Newsletter of the Golf Course Superintendents Association of New England, Inc. (2020 November/December)
Date: 2020-11
Collection: The Newsletter of the Golf Course Superintendents Association of New England, Inc.

Title: Connecticut Clippings. Vol. 54 no. 2 (2020 October)
Date: 2020-10
Collection: Connecticut Clippings

Title: The Newsletter of the Golf Course Superintendents Association of New England, Inc. (2020 September/October)
Date: 2020-09
Collection: The Newsletter of the Golf Course Superintendents Association of New England, Inc.

Title: The Newsletter of the Golf Course Superintendents Association of New England, Inc. (2020 July/August)
Date: 2020-07
Collection: The Newsletter of the Golf Course Superintendents Association of New England, Inc.

Title: Interview of Dr. Walter Greason, Associate Professor and Chair of the Department of Educational Counseling and Leadership at Monmouth University
Creator: Greason, Walter
Date: 2020-06-23
Collection: Voices of the Black Imaginary
Description: Dr. Walter Greason, primary curator for Afrofuturist Design: From Ancient Dogon to Wakandan Futures exhibition and Associate Professor and Chair of the Department of Educational Counseling and Leadership at Monmouth University, speaks about his work with Kurt Wagner, Director of the Monmouth University Library, creating a series of Afrofuturism displays within the Library. Dr. Greason talked about the origins of the exhibit and how this project aligns with engagement with black speculative...
Show moreDr. Walter Greason, primary curator for Afrofuturist Design: From Ancient Dogon to Wakandan Futures exhibition and Associate Professor and Chair of the Department of Educational Counseling and Leadership at Monmouth University, speaks about his work with Kurt Wagner, Director of the Monmouth University Library, creating a series of Afrofuturism displays within the Library. Dr. Greason talked about the origins of the exhibit and how this project aligns with engagement with black speculative practice in his teaching and research. He is interviewed by Julian Chambliss, with whom he co-authored Cities Imagined: The African Diaspora in Media and History.
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Title: Tee to Green. Vol. 51 no. 3 (2020 May/June/July)
Date: 2020-05
Collection: Tee to Green

Title: The Newsletter of the Golf Course Superintendents Association of New England, Inc. (2020 May/June)
Date: 2020-05
Collection: The Newsletter of the Golf Course Superintendents Association of New England, Inc.

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