Welcome to the repository for University of Maryland research.

The Digital Repository at the University of Maryland (DRUM) collects, preserves, and provides public access to the scholarly output of the university. Faculty and researchers can upload research products for rapid dissemination, global visibility and impact, and long-term preservation.

  • Faculty may use DRUM to fulfill the Equitable Access to Scholarly Articles Authored by University Faculty policy, and in many cases may use it to fulfill open access requirements from grant funding agencies.
  • Departments can use DRUM to publish or distribute their working papers, technical reports, or other research material.
  • DRUM also includes all UMD theses and dissertations from 2003 forward.

To learn more about DRUM, and how you can make your research openly accessible to the public, visit our DRUM policies website.


Recent Submissions

(2023) Chen, Tzu-yi; Haggh-Huglo, Barbara H; Gowen, Bradford; Music; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
“Departure” is a starting point to examine how Franz Liszt responded to and expressed his life away from his homeland through the musical language of selected piano works. After his initial departure from Hungary, Liszt’s relocations, changes of occupation, and artistic vocations led to conflict and disillusionment and at the same time reawaken his creative craft and religious calling to God to which his emotional experiences and spiritual calling give witness. While the idea of departure in Liszt’s case often signifies a geographical separation, it also reflects the resulting inner conflict, which fundamentally shaped his choices of compositional tools that he used to express conformity or deviation from musical traditions. This study examines five spiritually influenced programmatic piano works dating from 1839 to 1877 in light of Liszt’s physical and musical departures and demonstrates how he infused an evolving selection of extramusical inspirations into his program music, forms, and harmonic language. It provides a timeline connecting the events of his life and his artistic development. The tension and conflict of his inner life and creativity, after many twists and turns, will be shown to have led to his reconciliation with his Catholic faith, but first led him to compose program music. Liszt encountered a variety of extramusical inspirations around the mid-1830s. His reading of literature, ranging from epic poems to poetry collections influenced him heavily. As a result, he began to conceptualize program music. All five examples discussed here drew inspiration from literary texts, but his symphonic poems were inspired by poetry and painting. After arriving in Weimar in 1848, he developed his program-music concept in his symphonic poems and in important published piano works including revisions of earlier piano works. He learned to be more selective in quoting from a program in his compositions—he typically included poetry to introduce musical scores or as inserted texts in musical scores—and in the mid-1850s, he further defined his thoughts on musical forms and programs in his essay of 1855, On Berlioz’s Harold in Italy. During his subsequent prolonged sojourn in Rome, the unexpected failure of his marriage plan and the loss of his two children brought heightened awareness of destiny and death. These tragic events led him to reduce the numbers of themes expressing different moods. That allowed him to delve into his quoted program more deeply, which he accomplished by experimenting freely with various harmonizations. In his programmatic works that were spiritually influenced, Liszt responded to the tension he felt between his Christian ideals and his worldly desires by the divine and the diabolical in his music, by including quoted literary texts in the score that inspired him, and by using harmonies based on different scales. His musical conception of the divine was inspired by the musical heritage of the Church, which he evoked with pentatonic and hexatonic (whole-tone) scales, Gregorian chant-inspired themes and melodies, and harmonizations based on the Church modes. In his spiritually inspired compositions, Liszt also favored F-sharp major, representing heaven, as his key of choice, and he balanced a selection of consonant or perfect intervals versus dissonant harmonies and diminished intervals based on his readings of spiritually inspired literature. In contrast, his diabolical side is manifested in tritones, diminished seventh chords, chromatic scales, unexpected modulations, and his “diabolical” themes, which were part of his programmatic plan and represented by thematic transformations. This study describes his nuanced compositional progress in his conception and application of new forms—a modified one-movement sonata form, a freely structured passacaglia theme and variation form embedding a recitative and answered by a chorale, a three- act dramatic form—and in his use of increasingly sophisticated compositional techniques. He transformed themes to advance the plot of the quoted poetry, composed melodies to ‘sing’ the syllables of an absent but musically implied and thus quoted text, and even deliberately placed the texts of a Lutheran chorale or from the Latin Bible within his musical scores to make his piano compositions resemble vocal or liturgical choral music. These observations show how Liszt’s physical departures from Hungary, Paris, Weimar, and Rome fundamentally stimulated his artistic growth, in that his resulting life as sinner and saint, and his inner spiritual conflicts awakened both his diabolical nature and his ultimate search for the divine. Liszt succeeded in representing his strongly felt inner departures with deeply informed imagination in his piano music. I performed these five compositions on February 16, 2021, in Gildenhorn Recital Hall at the University of Maryland. Both live and studio recordings of this performance can be found in the Digital Repository at the University of Maryland.
Oceanic Electrical Conductivity Variability From Observations and Its Budget From an Ocean State Estimate
(Wiley, 2022-09-12) Trossman, D. S.; Tyler, R. H.
Because spatio-temporal variations in ocean heat content (OHC) are strongly predicted by ocean conductivity content (OCC) over most of the global ocean, we analyze the dynamical budget and behavior of the electrical conductivity of seawater. To perform these analyses, we use an ocean-model state estimate designed to accurately represent long-term variations in ocean properties in a dynamically and kinematically consistent way. We show that this model accurately reproduces the spatio-temporal variations in electrical conductivity seen in satellite-derived data and in a seasonal climatology product derived from in-situ data, justifying use of the model data to perform further analyses. An empirical orthogonal function analysis suggests that the vast majority of the variance in OHC and OCC can be explained by similar mechanisms. The electrical conductivity budget's most important term is the temperature forcing tendency term, suggesting that ocean heat uptake is the mechanism responsible for the strong relationship between OCC and OHC.
The endoglycosidase activity of Dispersin B is mediated through electrostatic interactions with cationic poly-β-(1→6)-N-acetylglucosamine
(Wiley, 2022-09-09) Breslawec, Alexandra P.; Wang, Shaochi; Monahan, Kathleen N.; Barry, Lucas L.; Poulin, Myles B.
Bacterial biofilms consist of bacterial cells embedded within a self-produced extracellular polymeric substance (EPS) composed of exopolysaccharides, extra cellular DNA, proteins and lipids. The enzyme Dispersin B (DspB) is a CAZy type 20 β-hexosaminidase enzyme that catalyses the hydrolysis of poly-N-acetylglucosamine (PNAG), a major biofilm polysaccharide produced by a wide variety of biofilm-forming bacteria. Native PNAG is partially de-N-acetylated, and the degree of deacetylation varies between species and dependent on the environment. We have previously shown that DspB is able to perform both endo- and exo-glycosidic bond cleavage of PNAG depending on the de-N-acetylation patterns present in the PNAG substrate. Here, we used a combination of synthetic PNAG substrate analogues, site-directed mutagenesis and in vitro biofilm dispersal assay to investigate the molecular basis for the endo-glycosidic cleavage activity of DspB and the importance of this activity for dispersal of PNAG-dependent Staphylococcus epidermidis biofilms. We found that D242 contributes to the endoglycosidase activity of DspB through electrostatic interactions with cationic substrates in the −2 binding site. A DspBD242N mutant was highly deficient in endoglycosidase activity while maintaining exoglycosidase activity. When used to disperse S. epidermidis biofilms, this DspBD242N mutant resulted in an increase in residual biofilm biomass after treatment when compared to wild-type DspB. These results suggest that the de-N-acetylation of PNAG in S. epidermidis biofilms is not uniformly distributed and that the endoglycosidase activity of DspB is required for efficient biofilm dispersal.
Whistler Waves Associated With Electron Beams in Magnetopause Reconnection Diffusion Regions
(Wiley, 2022-09-12) Wang, Shan; Bessho, Naoki; Graham, Daniel B.; Le Contel, Olivier; Wilder, Frederick D.; Khotyaintsev, Yuri V.; Genestreti, Kevin J.; Lavraud, Benoit; Choi, Seung; Burch, James L.
Whistler waves are often observed in magnetopause reconnection associated with electron beams. We analyze seven MMS crossings surrounding the electron diffusion region (EDR) to study the role of electron beams in whistler excitation. Waves have two major types: (a) Narrow-band waves with high ellipticities and (b) broad-band waves that are more electrostatic with significant variations in ellipticities and wave normal angles. While both types of waves are associated with electron beams, the key difference is the anisotropy of the background population, with perpendicular and parallel anisotropies, respectively. The linear instability analysis suggests that the first type of wave is mainly due to the background anisotropy, with the beam contributing additional cyclotron resonance to enhance the wave growth. The second type of broadband waves are excited via Landau resonance, and as seen in one event, the beam anisotropy induces an additional cyclotron mode. The results are supported by particle-in-cell simulations. We infer that the first type occurs downstream of the central EDR, where background electrons experience Betatron acceleration to form the perpendicular anisotropy; the second type occurs in the central EDR of guide field reconnection. A parametric study is conducted with linear instability analysis. A beam anisotropy alone of above ∼3 likely excites the cyclotron mode waves. Large beam drifts cause Doppler shifts and may lead to left-hand polarizations in the ion frame. Future studies are needed to determine whether the observation covers a broader parameter regime and to understand the competition between whistler and other instabilities.
Salt-in-Salt Reinforced Carbonate Electrolyte for Li Metal Batteries
(Wiley, 2022-08-30) Liu, Sufu; Zhang, Weiran; Wan, Hongli; Zhang, Jiaxun; Xu, Jijian; Rao, Jiancun; Deng, Tao; Hou, Singyuk; Nan, Bo; Wang, Chunsheng
The instability of carbonate electrolyte with metallic Li greatly limits its application in high-voltage Li metal batteries. Here, a “salt-in-salt” strategy is applied to boost the LiNO3 solubility in the carbonate electrolyte with Mg(TFSI)2 carrier, which enables the inorganic-rich solid electrolyte interphase (SEI) for excellent Li metal anode performance and also maintains the cathode stability. In the designed electrolyte, both NO3− and PF6− anions participate in the Li+-solvent complexes, thus promoting the formation of inorganic-rich SEI. Our designed electrolyte has achieved a superior Li CE of 99.7 %, enabling the high-loading NCM811||Li (4.5 mAh cm−2) full cell with N/P ratio of 1.92 to achieve 84.6 % capacity retention after 200 cycles. The enhancement of LiNO3 solubility by divalent salts is universal, which will also inspire the electrolyte design for other metal batteries.