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The Space Truck: Unloading Challenges of the SpaceX Starship
No full textAs the SpaceX Starship test program progresses, the number of conceptual and actual planned missions to use the capabilities of the vehicle are proposed and worked on. This paper discusses challenges faced in actually utilizing the capability of heavy landing of 100 ton payloads. The stability of the vehicle, the footings of the lander, and the physical dimensions required to move such large payloads are discussed. Additionally, proposed solutions for handling cargo and lifting capabilities are presented
Multi-Element Analysis of Crude Oils from Wyoming and Gabon
No full textSingle Reaction Chamber Microwave Digestion, ICP-OES, and QQQ-ICP-MS are used to determine 55 major, minor, trace, and ultratrace elements in 18 crude oil samples. Of these samples, 11 are from the Minnelusa, Muddy, and Minnekahta reservoirs in the Powder River Basin, one is from the Phosphoria reservoir in the Bighorn Basin, all of which are located in Wyoming. Six other oils are from the Gamba and Dentale reservoirs in the offshore South Gabon Basin, West Africa. Elemental concentrations and ratios, hierarchical cluster analysis, and normalization of rare earth elements to Post-Archean Australian Shale in crude oils are utilized to fingerprint each oil, group them, and differentiate source rocks and their depositional environments. Using regional stratigraphy and studies around each oil field, specific source rocks are proposed for each identified cluster. Five of the Minnelusa reservoir and one Phosphoria reservoir oil samples are interpreted as being sourced from the Phosphoria Shale based on the geochemical interpretation of a marine-terrestrial anoxic to suboxic source. The three Muddy reservoir samples are interpreted to be derived from the Mowry Shale source rock based on the geochemical interpretation of a terrestrial suboxic to oxic source with minor marine input. The two remaining Minnelusa reservoir and one Minnekahta reservoir samples are interpreted as having the Middle Minnelusa source rock based on the geochemical interpretation of a marine anoxic shale-carbonatic source. The Gabon samples all appear to be from the same source rock, proposed to be the Melania Shale based on geochemical interpretation confirming the lacustrine source rock and regional studies identifying the Melania Shale as being the primary regional source. With the composition of each individual crude oil sample known, an attempt was also made to manually mix oils from both Wyoming and Gabon in known proportions. The mixtures were analyzed for elemental concentrations. The composition of each endmember oil and the mixtures were input to the ALLO-TRACE program to allocate the oils. The experiment did not yield the expected allocation, likely due to problems with the homogeneity of oils from Gabon yielding only small differences in elemental abundances, and the process involving high viscosity (at room temperature) oils. Additionally, homogeneity or immiscibility issues with the Wyoming oil mixtures is thought to have been a problem, as analyzed mixtures demonstrate that certain elements did not fall on mixing lines. It is advised that future procedures focus on ensuring homogeneity of mixtures and miscibility of endmembers, particularly when the samples are viscous. Experiments with low viscosity oils have proven successful for allocation in the past, so it is clear special treatment is required for higher viscosity oils
The Reed Quintet: A Study of the History of a New Woodwind Genre, with Analyses of Paul Dooley’s Warp & Weft and David Biedenbender’s Refraction
No full textIn my essay, I will explore the origins, history, and literature of the reed quintet. I will begin by describing why its configuration of clarinet, oboe, saxophone, bassoon, and bass clarinet provides new opportunities for performers and fresh opportunities of style and tonal color in comparison to the traditional wind quintet. Second, I will survey the beginnings of the reed quintet by reviewing the work of the pioneer Dutch reed quintet, Calefax. Third, I will consider how the success of the Calefax reed quintet and American Akropolis Reed Quintet has led to an explosion of reed quintet popularity, as evidenced by the creation of over seventy new reed quintets listed on the World Wide Reed Quintet Network page hosted by Calefax. Finally, I will analyze two pieces that have become standard repertoire for the reed quintet: Paul Dooley’s Warp & Weft and David Biedenbender’s Refraction
Exploring the Anti-PSMA CAR T Cell Therapy in Treating Rhabdoid Tumor and Prostate Cancer
No full textRhabdoid tumors and metastatic castration-resistant prostate cancer (mCRPC) are difficult-to-treat malignancies due to their resistance to current therapies and their immunosuppressive tumor microenvironments. In this thesis, we explored the use of Chimeric Antigen Receptor (CAR) T cell therapy, specifically targeting Prostate-Specific Membrane Antigen (PSMA), to address these therapeutic gaps. In the first part, we investigated PSMA expression in rhabdoid tumor cell lines and demonstrated, that anti-PSMA CAR T cells can effectively target and eradicate PSMA-positive rhabdoid tumors in both in vitro and in vivo models. These findings suggest a promising new therapeutic option for rhabdoid tumor patients, who currently face poor survival outcomes with existing treatments. In the second part, we examined strategies to enhance PSMA-targeted CAR T cell efficacy in prostate cancer. Specifically, we investigated the role of Coactivator-Associated Arginine Methyltransferase 1 (CARM1) in CAR T cell function. Our results showed that short-term pharmacological inhibition of CARM1 enzymatic activity led to increased T cell and CAR T cell proliferation without reducing cytotoxicity. This finding suggests a potential strategy to streamline CAR T cell production, improving the scalability of this therapy. Overall, this thesis contributes to the improvement of CAR T cell therapies for solid tumors, offering new insights into both therapeutic targeting and production efficiency
Leadership and School Turnaround in Urban Schools: Perspectives From a Secondary Leadership Team
No full textBackground: For decades, billions of federal dollars have been spent to transform habitually low-performing schools (Backstrom, 2019). The process to transform failing schools is called school turnaround. Kutash et al. (2010) defined school turnaround as a comprehensive intervention to make significant academic gains. The academic gains will position a school to transform into a high-performance campus. Backstrom (2019) noted that the lack of consistent leadership, high teacher turnover, the lack of systems that adhere to the needs of the campus, and an instructional model that identifies the needs of students are the three internal barriers that cause schools to fail. Purpose: This study aims to identify the leadership styles, competencies, and processes of one leader in a chronically failing urban middle school. The purpose of this study is also to identify the critical processes implemented by the leader of a middle school campus. Research Questions: (1) How does a turnaround leadership team make sense of their work as leaders? (2) How does a leadership team’s knowledge of transformational, transformative, and instructional leadership practices promote teacher effectiveness and lead to results in student achievement? Methods: The qualitative methods used to explore this single case study will explore the real-life experiences of one secondary leader and examine how they applied the transformational, transformative, and instructional leadership practices that promoted teacher effectiveness and led to student achievement. Results: Based upon the focus group interviews and the in-depth document analysis, the findings revealed that Change ISD, the turnaround leadership team, and teachers all wanted the same thing: change. The current leadership team and teachers stated the same thing: change and the continuous improvement of the campus. Conclusion: The principal must possess boundless energy, infectious optimism, high regard for students’ needs, and know where to focus the proper resources and energy to achieve the mission and vision. To do so, the leader must act as a catalyst of change while motivating followers, use data-informed decision-making, create and maintain a culture of collaboration, and hold everyone accountable for achieving the set goal
New Chemistries for Cost-Effective Synthesis of Highly Fluorescent Zinc Selenide Quantum Dots Using Air-Stable Zinc Precursors
No full textQuantum dots (QDs) are semiconductor nanocrystals with unique optical properties, holding vast potential for applications in optoelectronics, photovoltaics, and bioimaging. Traditionally, ZnSe QDs have been synthesized via the hot injection method, pioneered by Hines et al., using diethylzinc as a zinc precursor. While effective in producing highly luminescent QDs, this approach presents substantial challenges: diethylzinc is highly pyrophoric, expensive, and requires stringent safety protocols due to its explosive reaction with oxygen. Our research introduces a safer, cost-effective approach to synthesizing ZnSe QDs by replacing diethylzinc with air-stable zinc sources—zinc acetate and zinc chloride—while optimizing synthesis conditions by adding various co-solvents. Initially, we investigated zinc acetate as a precursor, evaluating co-solvents such as ethanol, propanol, butanol, hexanol, acetone, butanone, and ether with tri-n octylphosphine selenide (TOPSe) in a hot reactor containing hexadecylamine (HDA). Butanol emerged as the most effective co-solvent, yielding ZnSe QDs with a quantum yield (QY) of approximately 50% when preheated to 117°C, just below butanol’s boiling point. This result demonstrated that zinc acetate could effectively substitute diethylzinc, offering a safer, more economical path to producing competitive QDs. To further clarify the influence of co-solvent choice on QD quality, we systematically varied co-solvent volume fractions, observing that butanol produced QDs with narrower full-width at half maximum (FWHM) values in their photoluminescence spectra, signifying a more uniform particle size distribution. Additionally, we tested zinc chloride as an alternative precursor, combining it with acetone in a one-step injection method that achieved an outstanding quantum yield of 93%. This method harnessed acetone’s unique properties to facilitate uniform zinc distribution and effective nucleation, while the formation of hydrochloric acid as a byproduct promoted surface passivation, resulting in enhanced optical properties. Characterization techniques, including transmission electron microscopy (TEM), X-ray diffraction (XRD), and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, confirmed the zinc-blende crystal structure and effective surface passivation by HDA. Our findings demonstrate the feasibility of using air-stable precursors like zinc acetate and zinc chloride for safer, cost-effective ZnSe QD synthesis, highlighting the role of co-solvents in optimizing QD growth and quality. This study advances nanomaterials research, paving the way for integrating ZnSe QDs into advanced optoelectronic applications
Genetic Algorithm-Enhanced Direct Method in Protein Crystallography
No full textDirect methods based on iterative projection algorithms can determine protein crystal structures directly from X-ray diffraction data without prior structural information. However, traditional direct methods often converge to local minima during electron density iteration, leading to reconstruction failure. Here, we present an enhanced direct method incorporating genetic algorithms for electron density modification in real space. The method features customized selection, crossover, and mutation strategies; premature convergence prevention; and efficient message passing interface (MPI) parallelization. We systematically tested the method on 15 protein structures from different space groups with diffraction resolutions of 1.35∼2.5 Å. The test cases included high-solvent-content structures, high-resolution structures with medium solvent content, and structures with low solvent content and non-crystallographic symmetry (NCS). Results showed that the enhanced method significantly improved success rates from below 30% to nearly 100%, with average phase errors reduced below 40°. The reconstructed electron density maps were of sufficient quality for automated model building. This method provides an effective alternative for solving structures that are difficult to predict accurately by AlphaFold3 or challenging to solve by molecular replacement and experimental phasing methods. The implementation is available on Github
Simulating Internet of Things Mobile Ad-Hoc Networks with Distributed Ledger Technology: "Which DLT is Best?"
No full textInternet of Things (IoT) and Distributed Ledger Technologies (DLTs), are both young fields that are especially suited to covering low-power decentralized environments. We identify an under-studied niche of IoT Mobile Ad-hoc NETworks (MANETs) to best utilize DLTs, and challenge ourselves to put an entire cryptographically secure DLT on a \$46 Arduino MKR WAN 1310. To accomplish this we create an open-source simulator for IoT-MANETs with several customizable modules: simple geo-spatial map, multiple DLT architectures, 3 wireless networks, consensus algorithms, mobile agent properties, storage optimizations, and Peer to Peer (P2P) gossip settings. We compare blockchains, Directed Acyclic Graphs (DAGs), HashGraphLight (a novel IoT-derivative of HashGraph) across Proof of Work (PoW) and Proof of Location (PoL). We then optimize the storage capacities, P2P set reconciliation, data throughput and battery consumption to accommodate the Arduino. Most notably along the way we illustrate that most DLTs throughput scale positively with denser networks, transaction redundancy is the biggest threat to storage overhead, design a two-stage set reconciliation answer for our uniquely bottle-necked environment, and prove that Long-Range Wide-area Network (LoRaWAN) is not viable for a gossip protocol. Our major contributions are: proving the general scalability of DLTs in low power IoT-MANET environments, identifying the bottleneck in P2P gossip, creating the first mobile DLT simulator, and comparing different DLTs/consensus algorithms. Ultimately, our results urge future projects to reject classical PoW and blockchains for more customizable solutions. The simulator can compare and contrast the properties of potential DLT architectures and answer: "What DLT is best?
Structure and Narrative in the Fourth Movement of the Quintet in F minor for Piano and Strings, op. 34, by Johannes Brahms
No full textIrony, as a musical expression, underscores much of 19th century music. Exploring the interaction between structure and narrative in the fourth movement of Quintet in F minor for Piano and Strings, op. 34, by Johannes Brahms, this study argues that the movement uses irony as an aesthetic framework while relying on tragedy as the chief narrativity within the subjectivity of the virtual agent. Drawing upon Byron Almén’s theoretical model of narrative archetypes and Hepokoski and Darcy’s Sonata Theory, the analysis examines sonata form deformations in the fourth movement, exploring how disruptions in sonata form trajectory correlate with an emergent expression of irony in the music. In examining the trajectory of virtual agents implied in the movement, I look toward irony as an aesthetic framework within which I construct the logic for linking actions with particular agents, and identify marked moments which are helpful for unveiling musical meaning in the reading. To contextualize this interpretation, the first part of the document situates historically the important position that Brahms’s Piano Quintet occupies in the survey of chamber music and the ways in which this work contributes significantly to the genre of the Piano Quintet. Following that is a comprehensive analysis of the fourth movement of Brahms’s Piano Quintet, in which the analysis examines how sonata form deformations imply the trajectory of a virtual agent, resulting in the work’s ironic narrative profile. The Sonata Theory of Hepokoski and Darcy establishes the norms and specifies the normative trajectory and cadential goals expected of a sonata form. When formal tensions are dialectically unresolved, irony may manifest as incongruencies of expectation and realization; in other words, a subversion of the normative or a shattering of hopes. In this movement, irony manifests through the following ways: 1) the rhetoric of suppression occurring throughout the movement (foreshadowed in the Intro!); 2) the use of structural and temporal discontinuities, such as post MC-interpolation; 3) the tri-modular structure of S-zone connected with the concept of S-theme failing to rise to the task of the sonata form; 4) the frequent recall of tragic signifiers from first and third movements; and lastly, 5) the use of a coda space that offers hope for redemption, only to embark on yet another tragic trajectory. Tragedy, as the master signifier of the musical discourse, explains the tragic trajectory undertaken by the virtual agent manifested through the musical expression of irony
Light-Driven Flow: Laser Streaming and Optothermocapillarity
No full textThe manipulation of fluid motion through light-driven techniques has emerged as a promising area of research, offering innovative approaches to controlling fluid dynamics. This dissertation focuses on two aspects of light-driven fluid motion: laser induced acoustic streaming and laser-induced thermocapillary flow. Harnessing the energy of laser light, these two techniques present unique advantages, such as non contact manipulation, precise control over fluid behavior, and the ability to operate in micro-scale environments. Through comprehensive investigations, this work aims to unravel the complex mechanisms behind these phenomena, offering new possibilities for fluid manipulation in applications such as microfluidics, biomedical devices, and advanced manufacturing. First, the mechanism of laser-induced acoustic streaming (laser streaming) is explored. This light-driven method involves the use of a pulsed nanosecond laser on a metal launch pad, creating a jet-like motion from the surface. Experimental results reveal the presence of non-harmonic ultrasound pulse trains, which correlate with the velocity of the streaming jet. It is demonstrated that this jet motion is driven by acoustic streaming, propelled by the radiation pressure gradient from attenuated acoustic waves. The origins of these ultrasound waves through a combined analytical modeling and numerical simulation. The second part of this work addresses the challenges posed by laser-generated non-harmonic acoustic streaming. Traditional acoustic streaming empowered by harmonic pressure waves are incompatible with the miniaturized nature of modern microfluidics. Meanwhile, the prevailing analytical tool for conventional acoustic streaming, i.e., the progressive approximation (perturbation) method, becomes invalid for non-harmonic fields. A new numerical methodology is developed by decomposing the ultrasound signal into a Fourier’s series and making it possible to apply the progressive approximation method. Numerical modeling of the laser streaming field is presented. The final part of this work focuses on laser-induced thermocapillary flow, which can cause varied surface deformations (local depression/local elevation) in liquid layers. This study identifies geometric confinement as a critical factor in determining surface behavior. Furthermore, the competition between interfacial thermocapillary flow and returning flow within the liquid dictates whether the surface rises or falls. A criterion for distinguishing between "thin" and "thick" liquid layers is established, with experimental results aligning with theoretical predictions