Structural Tuning of Two-Dimensional Perovskites at High Pressure

Two-Dimensional Perovskites are semiconductors and are of interest to researchers as the class of materials show great promise for innovating improvements to solar cells. The purpose of this experiment is to determine if a metastable change will occur in the materials: DPDAPbI4 and CMA2PbI4 upon compression to approximately 9 GPa. The experiment was conducted using diamond anvil cells (DAC) to apply static pressure to the materials. The pressure of the sample was then measured using ruby fluorescence. Then, FTIR or Raman spectroscopy acquisitions were obtained at various pressures. Subsequently, the data suggests that a metastable change did not occur. Additionally, the materials underwent a reversible amorphization and potential phase changes were observed in both materials

Ice Buckets to Proteins: Investigating the Role of matrin 3 in ALS

Amyotrophic Lateral Sclerosis, ALS, is a neurodegenerative disease characterized by the dysfunction of motor neurons in the spinal column, which prevents muscle movements and eventually, breathing. The prognosis is death typically within 2 to 5 years with only one drug available for treatment, Riluzole. This drug can only help select ALS patients as ALS is associated with many different protein mutations. One protein frequently found in ALS patient samples is TDP-43. These samples are from stress granules that form when there is toxicity in the cell. TDP-43 has been studied in an isolated context of its RNA-Recognition Motifs, RRM. These RRM domains are approximately 90 amino acids long, typically containing 2 alpha helices and 3 beta pleated sheets. Using this information, the secondary structure of the protein can be examined. The RRMs are highly specific regions that only bind to a certain DNA sequence, RNA sequence, or protein. Having an ordered region such as the RRM, allows for probing of the folding free-energy landscape, or the conformations that the protein takes as it is denatured to an unfolded state. This landscape is studied in hopes of locating an intermediate state; a state where either the secondary or tertiary structure is maintained, even though the protein continues to unfold. This intermediate conformation would be targeted for therapeutic development with the hope of forcing proteins in this state back to a native and functioning conformation. This would decrease the amount of misfolded protein and hopefully slow stress granule formation. RNA-binding ALS-linked protein matrin 3 is typically found alongside TDP-43 in stress granules of ALS patients. MATR3 gene mutations have been associated with RNA mismanagement. Repeating the isolated experiments performed with TDP-43, matrin 3 was examined for the presence of an intermediate state. Like TDP-43, matrin 3 has 2 RRMs and a tethered complex of the two RRMs. Unlike TDP-43, an intermediate state was not found. This brings to question the biological purpose of intermediate state conformations, which is investigated here

An experimental study to determine the effectiveness of the electric typewriter as compared with the manual typewriter in typing straight copy material, numbers, fill-in forms and tabulations

Thesis(Ed.D.)--Boston Universit

Quantum Control of Open Systems and Dense Atomic Ensembles

Controlling the dynamics of open quantum systems; i.e. quantum systems that decohere because of interactions with the environment, is an active area of research with many applications in quantum optics and quantum computation. My thesis expands the scope of this inquiry by seeking to control open systems in proximity to an additional system. The latter could be a classical system such as metal nanoparticles, or a quantum system such as a cluster of similar atoms. By modelling the interactions between the systems, we are able to expand the accessible state space of the quantum system in question.For a single, three-level quantum system, I examine isolated systems that have only normal spontaneous emission. I then show that intensity-intensity correlation spectra, which depend directly on the density matrix of the system, can be used detect whether transitions share a common energy level. This detection is possible due to the presence of quantum interference effects between two transitions if they are connected. This effect allows one to asses energy level structure diagrams in complex atoms/molecules. By placing an open quantum system near a nanoparticle dimer, I show that the spontaneous emission rate of the system can be changed ``on demand by changing the polarization of an incident, driving field. In a three-level, $\Lambda$ system, this allows a qubit to both retain high qubit fidelity when it is operating, and to be rapidly initialized to a pure state once it is rendered unusable by decoherence. This type of behaviour is not possible in a single open quantum system; therefore adding a classical system nearby extends the overall control space of the quantum system. An open quantum system near identical neighbours in a dense ensemble is another example of how the accessible state space can be expanded. I show that a dense ensemble of atoms rapidly becomes disordered with states that are not directly excited by an incident field becoming significantly populated. This effect motivates the need for using multi-directional basis sets in theoretical analysis of dense quantum systems. My results demonstrate the shortcomings of short-pulse techniques used in many recent studies. Based on my numerical studies, I hypothesize that the dense ensemble can be modelled by an effective single quantum system that has a decoherence rate that changes over time. My effective single particle model provides a way in which computational time can be reduced, and also a model in which the underlying physical processes involved in the system\u27s evolution are much easier to understand. I then use this model to provide an elegant theoretical explanation for an unusual experimental result called ``transverse optical magnetism\u27\u27. My effective single particle model\u27s predictions match very well with experimental data

Benefits Of Ketamine Versus Propofol In Acute Traumatic Brain Injuries With Elevated Intracranial Pressure

Ketamine is a widely used medication that can be administered for the delivery of anesthesia as well as analgesia while supporting hemodynamics. A commonly taught concept based on early research is that ketamine should not be administered to those with acute brain injuries. Early research had stated that ketamine can cause a dangerous increase in intracranial pressure (ICP) and thus a decrease in cerebral perfusion and oxygenation in those with traumatic brain injuries (TBI) (Takeshita et al., 1972). More recent research has shown that ketamine may be efficacious for patients with TBIs and can decrease ICP (Dengler et al., 2022). In comparison, the use of propofol for induction is a widely accepted and much more common practice for induction with the benefits of possibly avoiding a detrimental increase in ICP (Adembri et al., 2007). This literature review was conducted to identify the benefits and safety of cerebral hemodynamics with the use of ketamine versus propofol for induction in the adult population presenting for decompressive craniotomy. A literature review of confounding evidence has been conducted, including electronic bibliographic databases, relevant articles, and several anesthesia textbooks. In searching the databases the focus was on studies using ketamine and propofol with acute brain injuries and their effects on intracranial pressure in patients presenting for decompressive craniotomies. There are currently 31 research studies and systematic reviews included. Positive clinical outcomes, such as decreased ICP, hemodynamic control, and ideal pain control, were noted in many of the studies and within the literature. It appears that the use of ketamine does not increase ICP and may be just as efficacious as propofol for those presenting with TBI (Breindahl et al., 2021)

Advanced Space Transportation System Ground Operations Study

This paper presents partial results of a ground operations study for a series of Shuttle Derived Vehicles (SDV\u27s). The paper covers hardware and operational impacts for Kennedy Space Center (KSC) and Vandenberg Air Force Base (VAFB) resulting from processing any one of three different SDV configurations while maintaining Space Transportation System (STS) operations. The SDV configurations were assembled from Shuttle-type hardware (e.g., Solid Rocket Boosters (SRB\u27s), External Tanks (ET\u27s), Space Shuttle Main Engines (SSME\u27s) and Orbiter subsystems). One configuration incorporates a side mounted payload carrier/ propulsion module similar to the Orbiter on STS. A second configuration incorporates an inline payload carrier and propulsion module. The third configuration is the STS vehicle with an additional payload shroud structure located aft of the ET with approximately the same volume as the Orbiter Payload Bay. For each launch vehicle (LV) configuration and associated payloads, the paper presents the launch site impacts including new and modified facilities. Operational impacts were defined that included assessments of schedules, mixed (STS/SDV) fleet analysis, test procedures, and software

Multi-Group Invariance of the Conceptions of Assessment Scale Among University Faculty and Students

Conceptions are contextual. In the realm of education, conceptions of various constituent groups are often shaped over a period of a number of years during which time these groups have participated in educational endeavors. Specifically, conceptions of assessment are influenced by beliefs, actions, attitudes, understandings, and past experiences. These conceptions can impact both teaching and learning, and ultimately student achievement. Based on the past work of Gavin T. L. Brown (2004, 2006, 2008, 2010, & 2011) and Fletcher, Meyer, Anderson, Johnston, and Rees (2011) concerning conceptions of assessment held by educators and students in environments with a low-stakes assessment culture, this study re-examines the factor structure of the Conceptions of Assessment III (CoA-III) for faculty and students of higher education within a high-stakes assessment culture. Five models were initially considered based on past research by the above-mentioned researchers. Upon examining model fit of these five models, results indicated an acceptable model fit to the data collected from faculty and students within the United States. Furthermore, invariance testing elicited differences in how faculty (N = 159) and students (N = 404) of higher education conceptualize the purpose of assessment. Specifically, faculty members report that a primary purpose of assessment is for improvement of both teaching and learning. This group also suggested that assessment is useful for ensuring student accountability. However, results indicate that students associate assessment with accountability – both at the institutional and student levels. Furthermore, the data also suggest that a strong relationship between accountability and improvement exists. These results can be interpreted to mean that as accountability measures increase, there is a concomitant rise in the use of assessment for improvement purposes. Additional results of this study and implications of these findings for educational settings with high-stakes assessment cultures are discussed

Student Government and the University Administrative Agenda Alignment

Within institutions of higher education, shared governance is an essential component to a healthy functionality. Among the many stakeholders at these institutions, students are the largest in number and hold primacy. Participation in student governance establishes a sense of shared ownership over their communities while also providing a unique avenue for students to gain wisdom and develop critical skill sets. Senior administrators at these institutions have many inherent challenges due to an organization that is largely decentralized and autonomous. The purpose for conducting this study was to analyze Student Government Associations (SGA) at 8 select land-grant institutions of higher education in order to establish the extent of administrative agenda alignment after reviewing policy priorities for SGAs and their respective presidents. The study ultimately found minimal agenda alignment between student body presidents and university presidents. Student body presidents indicated that they did not necessarily anticipate alignment given the differences in their constituencies and most indicated positive relationships. These findings emphasize the importance of shared governance within these institutions. Positive relationships between SGAs and their presidents emphasize constructive communication and reciprocity between the subjects which leads to more buy-in by stakeholders and innovative ideas

On the Same Page: Student Government and the University Administrative Agenda Alignment

Within institutions of higher education, shared governance is an essential component to a healthy functionality. Among the many stakeholders at these institutions, students are the largest in number and hold primacy. Participation in student governance establishes a sense of shared ownership over their communities while also providing a unique avenue for students to gain wisdom and develop critical skill sets. Senior administrators at these institutions have many inherent challenges due to an organization that is largely decentralized and autonomous (Duderstadt, 2007). Regarding agenda setting, the Garbage Can Model (Cohen et al., 1972) was utilized as a theoretical framework. The purpose for conducting this study was to analyze Student Government Associations (SGA) at 8 select land-grant institutions of higher education in order to establish the answers to 4 research questions. (1) How do student leaders at select land-grant intuitions of higher education describe their policy priorities? (2) How do the presidents at the same institutions describe their priorities in select institutional or media documents? (3) To what extent are the agendas of SGAs and institutional presidents aligned? (4) How did student body presidents describe their working relationship with their respective institutional leader and does that impact agenda alignment? The answers to these questions were found utilizing a qualitative methodology. Specifically, official documents from the SGAs were reviewed and coded. Additionally, the student body presidents of 6 of the 8 universities in question were subjects in a semi-structured interview. Finally, official university documents, public remarks, and media coverage were analyzed and coded to establish the policy agendas for each institution’s president. The study found that Student Government Associations conduct policy implementation in the form of organizational management as the most prominent agenda item. In addition to that, it was shown that SGAs prioritize campus infrastructure improvements, campus safety, and the overall wellness of the student body. Presidents at the same institutions discussed issues related to research and innovation most prominently. They also prominently discussed campus infrastructure. The semi-structured interviews and document analysis showed a minimal alignment between the agendas. However, student body presidents indicated that they did not necessarily anticipate alignment given the differences in their constituencies. They also mostly described having positive relationships built upon mutual trust despite the lacking alignment. Institutional presidents were also found to rarely prioritize issues related to campus safety and sexual assault in direct contrast with SGAs. These findings emphasize the importance of shared governance within these institutions. Positive relationships between SGAs and their presidents emphasize constructive communication and reciprocity between the subjects which leads to more buy-in by stakeholders and innovative ideas