University Library, University of Illinois at Urbana-Champaign

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  • Africa - Nwana, S.P.C., 1966
    Digital Special Collections
    Creator
    • Nwana. S.P.C.
    • von Foerster, Heinz
    Date
    1966
    Description
    Math, 35.44%
  • PRECISE DETERMINATION OF THE ISOTOPIC RATIOS OF HC3N_x000d_ IN THE MASSIVE STAR-FORMING REGION Sgr B2(M)
    Scholarship
    Creator
    Oyama, Takahiro
    Description
    Isotopic ratio is a critical parameter in understanding galactic chemical evolution. In addition, carbon isotopic ratio of an organic molecule reflects its formation mechanism. In the present study, we observed the simplest cyanopolyyne chem{HC_3N} and its isotopomers in the massive star-forming region Sgr B2(M) with Nobeyama 45 m radio telescope. The column density and the rotational temperature of chem{HC_3N} were determined to be 1.6$times$10$^{15}$ cm$^{-2}$ and 163 K, respectively. The ratios of the column densities for the $^{13}$C isotopomers were derived to be [chem{H^{13}CCCN}]:[chem{HC^{13}CCN}]:[chem{HCC^{13}CN}] = 1:1.03(4):0.99(3), where the rotational temperature was fixed to that of HC$_3$N. The ratios are almost the same, suggesting no isotopic fractionation for the specific carbon atoms in HC$_3$N. Therefore, it is considered that the $^{13}$C isotope exchange reactions do not contribute to make difference among the column densities of the three $^{13}$C isotopomers in the relatively warm region of Sgr B2(M). In contrast, the reported ratios in TMC-1 and L1527 are 1:1.0(1):1.4(2)footnote{S. Takano $et$ $al$., $Astron$. $Astrophys$. {bf 329}, 1156 (1998).} and 1:1.01(2):1.35(3),footnote{M. Araki $et$ $al$., $ApJ$ {bf 833}, 291 (2016).} respectively, where the ratios show higher abundance of HCC$^{13}$CN._x000d_ _x000d_ We also observed the transitions in the vibrational excited states of chem{HC_3N}. The rotational temperature of 362 K in the $nu_4$, $nu_5$, $nu_6$ and $nu_7$ excited states was obviously different from that of the vibrational ground state.
  • SUB-DOPPLER ROVIBRATIONAL SPECTROSCOPY OF THE H3+ CATION AND ISOTOPOLOGUES
    Scholarship
    Creator
    Markus, Charles R.
    Description
    Molecular ions play a central role in the chemistry of the interstellar medium (ISM) and act as benchmarks for state of the art textit{ab initio} theory. The molecular ion H$_3^+$ initiates a chain of ion-neutral reactions which drives chemistry in the ISM, and observing it either directly or indirectly through its isotopologues is valuable for understanding interstellar chemistry. Improving the accuracy of laboratory measurements will assist future astronomical observations. H$_3^+$ is also one of a few systems whose rovibrational transitions can be predicted to spectroscopic accuracy ($
  • ASTROCHEMICALLY RELEVANT MOLECULES IN THE W-BAND REGION
    Scholarship
    Creator
    Arenas, Benjamin E
    Description
    The interplay between laboratory spectroscopy and observational astronomy has allowed for the chemical complexity of the interstellar medium (ISM) to be explored. Our laboratory studies involve the measurement of the rotational spectra of commercially available samples in the region 75-110 GHz, thus covering a portion of Band 3 of the Atacama Large Millimeter/submillimeter Array (ALMA). Up until recently, we have concentrated on medium-sized (5 to 9 heavy atoms) nitrogen- and oxygen-containing molecules and their vibrationally excited states. Examples include amino alcohols, such as alaninol (2-amino-1-propanol), and cyanides. Further, we have extended the capabilities of our segmented chirped-pulse spectrometer $[$1$]$ with electrical discharge apparatus. We present here the recent results from our set-up, including the typical rotational spectra of astrochemically relevant samples and the discharge-enabled rotational spectroscopy of mixtures of simple organic molecules. These experimental results have yielded transitions that will facilitate the detection of these molecules in the ISM with ALMA, and the discharge experiments should allow us to consider formation pathways of organic molecules from smaller building blocks. \_x000d_ \_x000d_ $[$1$]$ B.E. Arenas, S. Gruet, A.L. Steber, B.M. Giuliano, M. Schnell, Phys. Chem. Chem. Phys. 19 (2017) 1751-1756.
  • COLLISON-INDUCED ABSORPTION OF OXYGEN MOLECULE AS STUDIED BY HIGH SENSITIVITY SPECTROSCOPY
    Scholarship
    Creator
    Kashihara, Wataru
    Description
    Oxygen dimol is transiently generated when two oxygen molecules collide. At this short period, the electron clouds of molecules are distorted and some forbidden transition electronic transitions become partially allowed. This transition is called CIA (Collision-induced absorption). There are several CIA bands appearing in the spectral region from UV to near IR. Absorption of solar radiation by oxygen dimol is a small but significant part of the total budget of incoming shortwave radiation. However, a theory predicting the lineshape of CIA is still under developing._x000d_ In this study, we measured CIA band around 630 nm that is assigned to optical transition, a$^{1}$$Delta$$_{g}$(v=0):a$^{1}$$Delta$$_{g}$(v=0)-X$^{3}$$Sigma$$_{g}$$^{-}$(v=0):X$^{3}$$Sigma$$_{g}$$^{-}$(v=0) of oxygen dimol. CRDS(Cavity Ring-down Spectroscopy) was employed to measure weak absorption CIA band of oxygen. Laser beam around 630 nm was generated by a dye laser that was pumped by a YAG Laser. Multiple reflection of the probe light was performed within a vacuum chamber that was equipped with two high reflective mirrors. We discuss the measured line shape of CIA on the basis of collision pair model._x000d_
  • THE MICROWAVE SPECTRA AND MOLECULAR STRUCTURES OF 2-(TRIFLUOROMETHYL)-OXIRANE AND 2-VINYLOXIRANE, TWO CANDIDATES FOR...
    Scholarship
    Creator
    Marshall, Mark D.
    Description
    The conversion of enantiomeric molecules into spectroscopically distinct diasteromeric complexes has been proposed as a promising new means for chiral analysis. The success of this method requires the characterization of potential chiral tags as well as demonstrations of the feasibility and power of the technique. 2-(trifluoromethyl)- and 2-vinyloxirane are chiral molecules with simple, hyperfine-free spectra. They are high vapor pressure liquids that can easily be incorporated into a free jet expansion for complex formation and spectroscopic analysis, and they are commercially available in enantiomerically pure forms as well as racemic mixtures. The microwave spectra of these two molecules and their carbon and oxygen atom substitution structures are obtained as well as the spectrum and structure of the 2-(trifluoromethyl)-oxirane-argon complex.
  • INFRARED SPECTRA OF PROTONATED QUINOLINE (1-C9H7NH+) IN SOLID PARA-HYDROGEN
    Scholarship
    Creator
    Tseng, Chih-Yu
    Description
    Large protonated polycyclic aromatic hydrocarbons (H$^{+}$PAH) and polycyclic aromatic nitrogen heterocycles (H$^{+}$PANH) have been proposed as possible carriers of unidentified infrared (UIR) emission bands from galactic objects. The nitrogen atom in H$^{+}$PANH is expected to induce a blue shift of the C=C stretching band near 6.2 $mu$m so that their emission bands might agree with the UIR band better than those of H$^{+}$PAH._x000d_ _x000d_ In this work, we report the IR spectrum of protonated quinoline and its neutral species measured upon electron bombardment during deposition of a mixture of quinoline and textsl{para}-hydrogen at 3.2 K. New features were assigned to 1-chem{C_9H_7NH}$^{+}$ and 1-chem{C_9H_7NH}, indicating that the protonation and hydrogenation occur at the N-atom site. The intensities of features of 1-chem{C_9H_7NH}$^{+}$ diminished when the matrix was maintained in darkness for 10 h, whereas those of 1-chem{C_9H_7NH} increased. Spectral assignments were made according to comparison of experimental results with anharmonic vibrational wavenumbers and IR intensities calculated with the B3LYP/6-311++G(d,p) method. Although agreement between the observed spectrum of 1-chem{C_9H_7NH}$^{+}$ and the UIR emission bands is unsatisfactory, presumably because of the small size of quinoline, we did observe C=C stretching bands at 1641.4, 1598.4, 1562.0 wn, blue-shifted from those at 1618.7, 1580.8, 1510.0 wn of the corresponding protonated PAH (C$_{10}$H$_{9}$$^{+}$), pointing to the direction of the UIR bands._x000d_
  • ROVIBRATIONAL QUANTUM DYNAMICS OF THE METHANE-WATER DIMER
    Scholarship
    Creator
    Sarka, János
    Description
    The challenging quantum dynamical description of the CH$_4$·H$_2$O complex has been solved variationallyfootnote{ J. Sarka, A. G. Császár, S. C. Althorpe, D. J. Wales and E. Mátyus, Phys. Chem. Chem. Phys. 18, 22816 (2016).}_x000d_ to provide theoretical explanation and assignment to the high-resolution spectroscopic measurements of the methane-water dimer carried out some twenty years ago.footnote{ L. Dore, R. C. Cohen, C. A. Schmuttenmaer, K. L. Busarow, M. J. Elrod, J. G. Loeser and R. J. Saykally, J. Chem. Phys. 100, 863 (1994).}_x000d_ The computational results are in excellent agreement with the reported experimental transitions and the experimentally observed reversed rovibrational sequences, i.e., formally negative rotational excitation energies, _x000d_ are also obtained in the computations. In order to better understand the origin of these peculiar features in the energy-level spectrum, we studiedfootnote{ J. Sarka, A. G. Császár and E. Mátyus, Phys. Chem. Chem. Phys. accepted for publication (2017).} _x000d_ all four possible combinations of the light and heavy isotopologues of methane and water and analyzed their rovibrational states using two limiting model systems:_x000d_ the rigidly rotating (RR) molecule and the coupled rotor (CR) system corresponding to the coupling of the two rotating monomers._x000d_ _x000d_ All rovibrational quantum dynamical computations$^{a,c}$ were carried out with rigid monomers and $J$ = 0,1,2 total angular momentum quantum numbers using the fourth-age quantum chemical code _x000d_ GENIUSHfootnote{ E. Mátyus, G. Czakó and A. G. Császár, J. Chem. Phys. 130, 134112 (2009).}$^{,}$footnote{C. Fábri, E. Mátyus and A. G. Császár, J. Chem. Phys. 134, 074105 (2011).}_x000d_ and two different methane-water potential energy surfaces_x000d_ (PES).footnote{O. Akin-Ojo and K. Szalewicz, J. Chem. Phys. 123, 134311 (2005).}$^{,}$footnote{C. Qu, R. Conte, P. L. Houston and J. M. Bowman, Phys. Chem. Chem. Phys. 17, 8172 (2015).}_x000d_ The numerical and formal analysis of the wave functions give insight into a fascinating complex world worth for further theoretical and experimental inquiries._x000d_ _x000d_ _x000d_ _x000d_ _x000d_ _x000d_ _x000d_ _x000d_ _x000d_ _x000d_ _x000d_ _x000d_
  • INFRARED SPECTROSCOPY OF DISILICON-CARBIDE, Si2C
    Scholarship
    Creator
    Giesen, Thomas
    Description
    Small silicon and carbon containing molecules are thought to be important building blocks of interstellar grains. Some of them have been detected in circumstellar environments of late-type stars by means of rotational spectroscopy e.g., SiC, SiC$_2$, Si$_2$C, c-SiC$_3$, SiC$_4$, while centro-symmetric species, e.g., C$_3$, C$_4$, C$_5$, Si$_2$C$_2$, Si$_2$C$_3$, can only be detected by vibrational transitions, mainly in the infrared. _x000d_ In view of a new generation of high resolution infrared telescope instruments, e.g., EXES (Echelon-Cross-Echelle Spectrograph) onboard SOFIA (Observatory for Infrared Astronomy) and TEXES (Texas Echelon Cross Echelle Spectrograph) at the Gemini-North observatory, accurate laboratory data of small silicon-carbides in the infrared region are of high demand. In this talk we present first laboratory data of the Si$_2$C asymmetric stretching mode at 1200 cm$^{-1}$. A pulsed Nd:YAG-laser is used to vaporize a solid target of silicon exposed to a dilute sample of methane in helium buffer gas. Si$_2$C is formed in an adiabatic expansion of a supersonic jet and radiation of a quantum cascade laser is used to record rotationally resolved spectra. To date, 160 ro-vibrational lines and have been assigned to the asymmetric stretching vibration of Si$_2$C, and derived molecular parameters are in excellent agreement with ab initio calculations. In our global fit analysis recently published microwave laboratory data (McCarthy {it et al.} 2015)footnote{McCarthy M.C., Baraban J.H., Changala P.B., Stanton J.F., Martin-Drumel M.A, Thorwirth S., et al., {it J. Chem. Phys. Lett.} {bf6}, 2107–2111 (2015).} and astronomical data (Cernicharo {it et al.} 2015)footnote{Cernicharo J., McCarthy M.C., Gottlieb C.A., Agundez M., Velilla Prieto L., Baraban J.H., et al. {it Astrophys. J. Lett.} {bf 806},L3 (2015).} were taken into account. Our new results allow for the identification of Si$_2$C by means of high resolution infrared astronomy towards the warm background of carbon-rich stars._x000d_ _x000d_ _x000d_ _x000d_ _x000d_
  • VIBRATIONALLY EXCITED c-C3H2 RE-VISITED: NEW LABORATORY MEASUREMENTS AND THEORETICAL CALCULATIONS
    Scholarship
    Creator
    Gupta, Harshal
    Description
    Cyclopropenylidene, $c$-C$_3$H$_2$, is one of the more abundant organic molecules in the interstellar medium, as evidenced from astronomical detection of its single $^{13}$C and both its singly- and doubly-deuterated isotopic species. For this reason, vibrational satellites are of considerable astronomical interest, and were the primary motivation for the earlier laboratory work by Mollaaghababa and co-workers [1].\_x000d_ indent The recent detection of intense unidentified lines near 18,GHz in a hydrocarbon discharge by FT microwave spectroscopy has spurred a renewed search for the vibrational satellite transitions of $c$-C$_3$H$_2$. Several strong lines have been definitively assigned to the $v_6$ progression on the basis of follow-up measurements at 3,mm, double resonance and millimeter-wave absorption spectroscopy, and new theoretical calculations using a rovibrational VMP2 method [2] and a high-quality ab initio potential energy surface. The treatment was applied to several excited states as well as the ground state, and included deperturbation of Coriolis interactions._x000d_ _x000d_ [1] R. Mollaaghababa, C.A. Gottlieb, J. M. Vrtilek, and P. Thaddeus, textit{J. Chem. Phys.}, textbf{99}, 890-896 (1992)._x000d_ _x000d_ [2] P.~B. Changala and J.~H. Baraban. textit{J. Chem. Phys.}, textbf{145}, 174106 (2016)._x000d_ _x000d_
  • Can fair use be adequately taught to librarians? Assessing librarians’ confidence and comprehension in explaining fair...
    Scholarship
    Creator
    Benson, Sara R.
    Description
    Fair use is often viewed as a topic too difficult for librarians and library staff to engage with and, hence, avoided altogether. However, with the right training, librarians can learn how to employ fair use in their daily work. This study utilized testing both before and after an expert led fair use training session in order to measure both librarian confidence and comprehension of fair use. The results, though limited in scope, provide encouraging evidence that librarians can tackle the concept of fair use when provided with appropriate training. Both the level of confidence and the level of comprehension rose after the librarian participants were provided with training, indicating that the training did indeed have impact. Further evidence of impact was evidenced by the survey distributed two weeks after the training wherein some librarians noted that they had had the opportunity to utilize the skills learned in the training workshop during their daily work. The results, therefore, are encouraging and hopefully will lead to further training program development and implementation regarding fair use and other copyright issues in libraries.
  • Race and gender effects on leadership perceptions
    Scholarship
    Creator
    Petersen, Abigail Elizabeth
    Description
    The purpose of this study was to examine the effects of differences in the gender and racial identity of students on the perceived leader skill, motivation to lead, and leadership self-efficacy of themselves and other students with whom they collaborate in formal student organizations. The study investigated members of student organizations of a large, public, Midwestern research university. Results indicated strong positive ratings of male leaders by men in leadership self-efficacy and positive ratings of women leaders by women in leader skill and aspects of motivation to lead. Findings suggested that women representation in leadership positions will likely continue to rise in the future. The study also found that Asian Americans consistently rated themselves and others significantly lower in leadership scores compared to White individuals.
  • Probabilistic seismic demand models of RC bridge columns retrofitted with shape memory alloy spirals
    Scholarship
    Creator
    Deogekar, Pratik Sharad
    Description
    The breakdown of critical bridge infrastructure in past earthquakes has often been attributed to the failure of reinforced concrete (RC) bridge columns due to lack of flexural ductility. Despite the revision of structural design standards to accommodate the lessons learned from these earthquakes, a significant number of RC bridge columns, built prior to these revisions, are vulnerable to failure under moderate and high intensity earthquakes. Recent studies have shown that retrofitting these vulnerable RC bridge columns by applying lateral active confinement using shape memory alloy (SMA) spirals can significantly improve their ductility, resulting in enhanced seismic performance. The research work done till date in this area is limited to exploring experimentally the efficacy of this new retrofit technique on a material and component level. In order to aid the implementation of this retrofit technique in actual construction practice, this thesis initiates the development of a performance-based-design framework for SMA retrofitted columns by creating seismic demand models which relate the intensity measure (IM) of an earthquake with the demand imposed by the earthquake on SMA retrofitted RC columns, which is quantified in terms of demand measures (DM). An array of vulnerable RC bridge columns, susceptible to flexural failure due to inadequate lateral confinement, is created using Latin hypercube sampling and 6 columns with varying time periods and reinforcement ratios are chosen. These columns are retrofitted with SMA spirals in their plastic hinge region and subjected to a suite of bi-directional ground motion records. The performance of the retrofitted columns is assessed using 4 DM including maximum drift, residual drift, an energy-based concrete damage index and a steel damage index based on low-cycle fatigue. The suitability of 8 IMs for the development of probabilistic demand models to predict the DMs is explored. The optimal IM, which predicts the DM with least uncertainty, is found to be a function of the fundamental period of the retrofitted columns. The final demand models, developed using the optimal IM, are presented and compared to understand the effect of lateral active confinement. The results indicate that increasing the confinement reduces the damage in concrete substantially while the damage associated with low-cycle fatigue of steel is also reduced. Higher levels of active confinement are also seen to be effective in reducing the residual drifts of long period columns.
  • Studies of new world treehoppers of the subfamily Centrotinae with emphasis on the Caribbean fauna (hemiptera:...
    Scholarship
    Creator
    Morris, Brendan O.
    Description
    The subfamily Centrotinae (Hemiptera: Membracidae) is an ancient group of treehoppers comprising over half of the known treehopper genera and is the only membracid lineage with a cosmopolitan distribution. Although higher-level morphological systematic analyses have greatly improved our understanding of this group, the relationships within the New World fauna remain unclear, particularly in light of recently described and still undescribed genera from Central America and the Caribbean islands. Bayesian phylogenetic analyses based on 115 morphological characters, nuclear ribosomal 28S DNA and protein-coding histone 3 (H3) gene sequence fragments were performed to test the monophyly of two centrotine tribes endemic to the Caribbean Islands, Nessorhinini and Monobelini. Many relationships were recovered with low node support or were unresolved; however, the results provide moderate support for a single colonization of the Greater Antilles by Mesoamerican ancestors.
  • Test boring reports: UI parade ground dormitory units, 1957
    Scholarship
    Description
    Soil test boring reports and correspondence concerning the site of a men's dormitory structure proposed for construction on parade grounds at UIUC. Papers dated 1957.
  • The relationship among mathematics anxiety, parental support and peer support in undergraduate students
    Scholarship
    Creator
    Leong, Ka Fai
    Description
    The study aims to examine the relationship among mathematics anxiety, parental support and peer support. Quantitative approach will be employed and undergraduate students will be asked to complete the surveys. Students will be accessed for the mathematics anxiety and the level of their parental and peer support. The study will help to address how mathematics anxiety, parental and peer support are related and give implication to the relationship.
  • Evaluation of Adaptive Signal Control Technology—Volume 2: Comparison of Base Condition to the First Year After...
    Scholarship
    Creator
    • Garshasebi, Behnoush
    • Jeon, Honjae
    • Liu, Xueying
    • Benekohal, Rahim F
    Description
    Field evaluation of adaptive signal control technologies (ASCT) is very important in understanding the system’s contribution to safety and operational efficiency. Data were collected at six intersections along the Neil Street corridor in Champaign, Illinois, before deployment of SynchroGreen, an ASCT system. The volume, delay, and queue length data from the field for the “before” conditions (which is 2013 data) were compared to the data from the first year after implementation conditions (which is 2015 data). The system was installed in early 2015 and fined tuned by the vendor to get the “best” performance. The field volumes were compared for 83 lane groups (approaches). While traffic volume on 48% of the lane groups significantly increased, 48% did not change significantly, and only 4% significantly decreased. The field delays were compared for 83 lane groups; out of which 22% showed significant increase, 64% showed no significant change, and 14% showed significant decrease. Queue length was compared for only 63 lane groups because the remaining 20 lane groups either did not have queue data, or the queue length was insignificant (two cars or less). Out of the 63 lane groups, 32% showed significant increase, but 49% showed no significant change, and 19% showed significant decrease in queue length. ASCT performance was evaluated based on the changes in volume, delay, and queue length combined. An overall performance indicator (PI) was determined as: Imp (Improved), Unch (Unchanged), Det (Deteriorated), or Mix (mixed results). Of the 83 lane groups analyzed, 51% showed improvement, 20% remained unchanged, 28% showed deterioration, and 1% showed a mixed result. The analyses indicated that ASCT made a compromise between the minor and major street performances and, in general, the minor street improvements were correlated with the major street deterioration or unchanged performances.
  • Test boring reports: Newman Foundation, 1957
    Scholarship
    Description
    Soil test boring reports and correspondence concerning UIUC's Newman Foundation, St. John's Catholic Chapel; papers dated 1957.
  • Test boring reports: miscellaneous University of Illinois campus buildings, dated 1951 - 1961
    Scholarship
    Description
    Soil test boring reports and correspondence about several miscellaneous UIUC campus building projects; papers dated 1951 - 1961.
  • Test boring reports: conditions of proposed Mura high-energy particle accelerator site, 1956
    Scholarship
    Description
    Soil test boring reports and correspondence concerning soil and geologic conditions of proposed Mura high-energy particle accelerator site at the University of Illinois; papers dated 1956.
  • Predicting Stock Price Movements from Annual Reports
    Scholarship
    Creator
    Zou, Daniel W.
    Description
    We propose a supervised machine learning system to learn from text and financial data and predict whether an asset will have positive, neutral, or negative excess returns one day after the release of a text document. Our system utilizes TF.IDF and non-negative matrix factorization to build document embeddings and an ensemble of gradient-boosted regression trees for classification. Our aim is to improve the performance of a benchmark classifier that uses past stock price history by digesting and extracting useful features from text data. We use a corpus containing over 100,000 Form 10-Ks and 10-Qs, which are annual and quarterly shareholder reports to the U.S. Securities and Exchange Commission (SEC) respectively. By incorporating textual features, we beat our baseline model significantly and present an asset-agnostic model for stock price movement predictions. Our work has implications for text analysis, corporate fraud detection, and algorithmic trading.
  • Unique Plastron Patterns of the State-endangered Blanding’s Turtle
    Scholarship
    Creator
    Mumm, Lauren
    Description
    Blanding’s turtles (Emydoideablandingii), an endangered species in Illinois, have experienced range-wide declines due to habitat loss, degradation, and fragmentation. The unique patterns on the plastron (bottom shell) along with hand-filed notches on the carapace (top shell) allow for identification of individual turtles. My research involved tracking, trapping or incidentally finding Blanding’s turtles in an area with a known existing population and establishing a baseline health assessment to aid in conservation efforts in Lake County, IL. Working with Lake County Forest Preserve District and through the College of Veterinary Medicine’s Wildlife Epidemiology Lab we collected blood and oral swabs for testing the wellness of both individuals and populations. By monitoring health our objective is to establish criteria that can be integrated into future conservation assessments of wild and captive populations.
  • NanoprismMosaic
    Scholarship
    Creator
    Satyavolu, Nitya S. R.
    Description
    The picture here represents a false-colored scanning electron microscope image of gold nanoprisms, each only a few nanometers thick, but sub-micron sized in lateral dimensions. The nanoprisms, each colored differently, look like chards of painted glass in a mosaic. Ideally, a successful synthesis would yield nanoprisms that are identical in shape and size, but a “bad” day in lab can occasionally result in something truly beautiful.
  • Test boring reports: machine tool lab, 1950
    Scholarship
    Description
    Soil test boring report, drawing and correspondence concerning a UIUC machine tools laboratory; papers dated 1950.
  • Test boring reports: mathematics center, 1963
    Scholarship
    Description
    Soil test boring reports and correspondence concerning a UIUC mathematics building; papers dated 1963.
  • Test boring reports: mechanical engineering building, 1944 - 49
    Scholarship
    Description
    Soil test boring reports and correspondence concerning a UIUC mechanical engineering building; papers dated 1944 - 1949.
  • Observation
    Scholarship
    Creator
    Holland, Robin L.
    Description
    When one engages in research, we transition, from being a gatherer of knowledge, to a creator of knowledge. The process of research by its very nature pushes its explorers to question dogmas and pioneer new fields, and rewards those with a careful and observant eye. History has shown us that the greatest scientific discoveries often arise from simple observations made by diligent and curious individuals, observations that were overlooked by others blinded by expectations, predictions, and assumptions. The above image is far from any monumental discovery, only the crystallized remains of a salty solution in a beaker left aside and forgotten. Albeit insignificant, something as simple as a disregarded beaker can still remind us to always be watching for an unexpected finding in the most unexpected of places, and that anything can give rise to little moments of beauty, but only if we are willing to look and see what science is showing us.
  • Searching for history
    Scholarship
    Creator
    Huck, Karen M.
    Description
    Open Educational Resource that teaches undergraduate students how to search the library catalog for books, the America: History and Life database for searching for scholarly journals and the Chronicling America free website in order to find newspaper articles from an earlier time period. This instructional material is meant for students in American History courses looking for source material for a research paper, but might also be adapted for other areas of research.
  • Transcendence
    Scholarship
    Creator
    Maxwell, Elizabeth
    Description
    This image depicts feline cancer cells growing in a cell culture. This type of cancer is very aggressive and difficult to treat. My research involves investigating a novel treatment delivery option against this type of cancer. Learning how to grow these cells in culture to test different doses of a chemotherapeutic drug was challenging and gave me insight into the aggressive cellular behavior of this cell types. It allowed me to delve into a whole new world of science that I couldn't have imagined and it gave me an appreciation for the ultimate goals of my research.
  • What's in Your Aquarium? Mollusks
    Scholarship
    Creator
    • Illinois Natural History Survey
    • Illinois-Indiana Sea Grant
    Description
    Do you know what's in your aquarium? Many aquarium mollusks are invasive if they make their way into the environment. This 4-panel brochure will help you learn which mollusks to avoid buying and which are a better choice.
  • Test boring reports: life sciences, unit 3, 1963
    Scholarship
    Description
    Soil test boring reports and correspondence concerning a UIUC life sciences building, unit #3; papers dated 1963.
  • Understanding longitudinal ADCP measurements to determine water velocities for open channel flow
    Scholarship
    Creator
    Banjavcic, Scott David
    Description
    Despite the advances in technology, the traditional standard of practice of measuring velocities in open channels relies on the historically proven methodology that was primarily focused on accurately determining the discharge of streams and rivers. The traditional standard of practice relies on time-averaged stationary measurements and transect measurements (performed for cross sections roughly perpendicular to the flow) to describe complex hydraulic processes. This research seeks to understand a longitudinal acoustic Doppler current profiler (ADCP) measurement approach as an alternative to the present ADCP measurement practice (collecting stationary measurements or measurements along transects). The growing need for precisely interpolated velocities at all points throughout a river reach necessitates a more spatially diverse approach to data collection. The author explores the hypothesis that longitudinal measurements can predict velocities for a river reach scale more effectively than collecting stationary measurements or measurements along transects. More precise velocity mapping for river reaches could have a direct impact on engineering topics such as determining areas of scour and deposition, estimating habitat suitability, calculating dispersion of pollutants, calibrating 2D and 3D hydrodynamic models, and more. The following research objectives increase the understanding of the longitudinal measurement approach in three specific areas: determining depth-averaged velocity for locations in a river reach, extending velocity interpolation to vertical velocity profiles, and utilizing the interpolated velocities to estimate bed shear stress for a river reach. The first research objective focusing on exploring depth-averaged velocity for locations in a river reach presents interpolated transect and longitudinal velocities and compares them to the known transect and stationary data. The two main variables explored to compare the data collection methods were data density and data collection effort. Data density was determined by theoretical transect spacings, which correspond to the standard practice of interpolating between transect measurements to determine depth-averaged velocities for an entire river reach. The transect spacing was defined in terms of dimensionless RiverWidths to allow the results from this research to be scaled to rivers of different sizes. For each data density (denoted in RiverWidths) that was investigated, the data collection effort time was determined for the transect and longitudinal data collection methods. It was very important to ensure equivalent measurement time (defined in this research as data collection effort time) and effort for all comparisons to present an accurate comparison of the stationary, transect, and longitudinal data collection methods. The results from this research objective indicate that the longitudinal interpolated velocities match the known data and mimic the cross section velocity trend better than the interpolated transect depth-averaged velocities. In addition, the interpolated longitudinal velocities were analyzed to determine an optimal data density. The following recommendations were developed to guide data collection efforts for transect and longitudinal ADCP data to reduce the average absolute relative error when interpolating depth averaged velocities. 1. The relationship between RiverWidth and the absolute relative error implies an increase in error of 1% to 2% per RiverWidth for the interpolated longitudinal depth-averaged velocities, and an increase in error of 2.5% to 5% per RiverWidth for the interpolated transect depth-averaged velocities. 2. The absolute relative error for interpolating longitudinal velocities is the same as for interpolating between transects when the longitudinal measurement passes are the same distance apart as the transects. 3. An increase in the average absolute relative error from 0.1% to 0.4% per meter spacing between longitudinal measurement passes was observed for the Pecatonica and St. Joseph rivers. The second research objective explores using transect and longitudinal ACDP measurements to interpolate velocities throughout the water column. Both dimensionless depth layers (which favor interpolating in layers that utilize velocities in similar positions in the water column) and elevation-difference defined depth (horizontal layering) were explored to test the effect of channel shape on velocity interpolation. In general, the difference between velocities interpolated using dimensionless depth versus elevation defined depth was less significant than the difference between interpolated velocities developed using the longitudinal data collection technique as opposed to the transect data collection method. The following observations provide guidance for using transect and longitudinal ACDP measurements to interpolate velocities throughout the water column. 1. The longitudinal measurement technique is a better alternative to interpolation between transect measurements for describing velocities at various depths and locations in a river reach. 2. The dimensionless depth layering approach is marginally better than layering by elevation difference (horizontal) for river reaches with significant bathymetric variation. The final research objective presents potential hydraulic applications for the depth-averaged velocities and vertical velocity profiles. Many hydraulic applications including: determining habitat suitability, characterizing secondary flow, estimating dispersion, determining bed shear stress, and others may benefit from ADCP data collection utilizing the longitudinal method along with the stationary and transect-focused methodology. This research objective focused on using the dimensionless depth velocity profiles developed by the previous research objective to estimate the bed shear stress. Bed shear stress is an important hydraulic parameter that affects deposition and scour, which directly impact navigation (among other things) in open channel flow. The following information can be gleaned from the bed shear stress estimates developed using the interpolated dimensionless depth longitudinal vertical velocity profiles. 1. Areas where the bed shear stress estimates were small were consistent with the low moving-bed velocities determined for the studied rivers. 2. There is significant error in the bed shear stress estimates in areas with complex bathymetry, which is consistent with the increased error observed in the vertical velocity profiles. 3. The error in the bed shear stress estimates suggests that longitudinal ADCP measurements should be used with caution in areas of complex bathymetry. Overall, this research concludes that the longitudinal data collection approach is very useful for generating depth-averaged velocities and vertical velocity profiles, and has significant value as an important tool for a hydrologist’s toolbox to better solve complex open channel flow problems.
  • Creditor rights, entrepreneurship, and productivity
    Scholarship
    Creator
    Ersahin, Nuri
    Description
    The first essay, Creditor Rights and Entrepreneurship: Evidence from Fraudulent Transfer Law, examines entrepreneurship following the adoption of modern-day fraudulent transfer laws in the United States. These laws remove the burden of proof from creditors attempting to claw back funds that were transferred out of failing businesses. They are particularly important for entrepreneurs whose personal assets are often commingled with those of the firm. Using establishment-level data from the U.S. Census Bureau, I document declines in startup entry, churning among entrants, and closures of existing ventures after the passage of these laws. Thus, strengthening creditor rights can impede entrepreneurial activity and the process of reallocating capital from failing to new businesses. In the second essay, Creditor Rights, Technology Adoption, and Productivity: Plant-Level Evidence, I analyze the impact of stronger creditor rights on productivity using plant-level data from the U.S. Census Bureau. Following the adoption of anti-recharacterization laws that give lenders greater access to the collateral of firms in financial distress, total factor productivity of treated plants increases by 2.6 percent. This effect is mainly observed among plants belonging to financially constrained firms. Furthermore, treated plants invest in capital of younger vintage and newer technology, and become more capital-intensive. My results suggest that stronger creditor rights relax borrowing constraints and help firms adopt more efficient production technologies. The third essay, Creditor Control Rights and Resource Allocation within Firms, examines the within-firm resource allocation and restructuring outcomes at firms violating debt covenants. We use establishment-level data from the U.S. Census Bureau to demonstrate that covenant violations are followed by reductions in employment, investment, and more frequent establishment closures among violating firms' noncore business lines and underperforming establishments. These changes are pronounced when key lenders have prior industry experience. Thus, refocusing operations and improving productive efficiency via resource reallocation are important channels through which enhanced creditor rights can facilitate the turnaround of firms in technical default.
  • The effects of distraction on amount of food consumed, food preference, and satiety
    Scholarship
    Creator
    Liguori, Carli A.
    Description
    Distracted eating is the intentional consumption of a meal while engaged in a secondary activity to the extent that the significance or memory of the meal is diminished. Limited published studies suggest distracted eating leads to increased intake; however, results of the present study do not support previous findings. The present study also aimed to assess the effects of distraction of food preference and perceptions of satiety. A randomized controlled crossover study was conducted with 120 healthy adults (age: 20.2 ± 1.4 years; 57% female; 48% white). Participants were randomly assigned to begin in either the distracted (DIS, n=55) or non-distracted (NON, n=65) test condition. In both conditions, participants were provided with miniature quiche. In DIS, participants consumed quiche while playing a Rapid Visual Information Processing (RVIP) task. In NON, participants ate without any distraction. Plates were weighed before and after consumption. After a 30-minute rest period, participants were offered a snack of grapes and miniature cookies and given 5 minutes to eat as much as they liked. The food was removed, and participants completed an exit survey assessing satiety and enjoyment of the meal. After a 1-week washout period, participants completed the opposite condition. A repeated measures analysis of variance was conducted (Statistical Package for the Social Sciences, version 23.0.0). Participants on average consumed 115.4 ± 5.5 g of quiche during DIS and 128.12 ± 4.4 g during NON. Those in DIS consumed significantly less (F(1, 117) = 11.78, p=.001). The relationship held when adjusting for initial condition (F(1, 117) = 28.786, p=.000) and gender (F(1, 116) = 30.441, p=.000). A significant interaction of initial condition was also detected (F(1, 117) = 19.689, p=.000). A repeated measures analysis of covariance (ANCOVA), controlling for initial condition and previous intake, was conducted to assess snack intake. Participants consumed 45.5 ± 11.1 g of grapes and 18.9 ± 12.4 g of cookies, on average. No significant difference in grape consumption (F(1, 113) = 1.366, p=.245) nor cookie consumption (F(1, 115) = 2.035, p=.156) was observed between groups. No significant difference in the proportion of grapes consumed (F(1, 113) = 1.632, p=.204) or proportion of cookies consumed (F(1, 115) = 1.682, p=.197) between groups was detected. An ANCOVA controlling for initial condition revealed a significant difference between groups for memory of quiche received (F(1, 116) = 30.737, p=.000) and memory of quiche consumed (F(1, 118) = 7.616, p=.007). Perceptions of satiety were measured using a 100mm Visual Analogue Scale (VAS). No statistically significant differences were observed between groups in perceptions of fullness (F(1, 109) = .600, p=.440), hunger (F(1, 109) = 1.213, p=.273), or enjoyment of the meal (F(1, 108) = 2.710, p=.103). Participants consumed significantly less food when distracted, on average. Memory of the meal was decreased when distracted, but no differences were observed in amount consumed or food preference at a future eating occasion. No difference in perceptions of satiety or enjoyment of the meal were observed. Findings may be due to testing distracted eating during breakfast, the novelty of the RVIP to participants, or the inclusion of male participants. Future research should aim to determine more conclusive results.
  • Analyzing & designing the security of shared resources on smartphone operating systems
    Scholarship
    Creator
    Demetriou, Soteris
    Description
    Smartphone penetration surpassed 80% in the US and nears 70% in Western Europe. In fact, smartphones became the de facto devices users leverage to manage personal information and access external data and other connected devices on a daily basis. To support such multi-faceted functionality, smartphones are designed with a multi-process architecture, which enables third-party developers to build smartphone applications which can utilize smartphone internal and external resources to offer creative utility to users. Unfortunately, such third-party programs can exploit security inefficiencies in smartphone operating systems to gain unauthorized access to available resources, compromising the confidentiality of rich, highly sensitive user data. The smartphone ecosystem, is designed such that users can readily install and replace applications on their smartphones. This facilitates users’ efforts in customizing the capabilities of their smartphones tailored to their needs. Statistics report an increasing number of available smartphone applications— in 2017 there were approximately 3.5 million third-party apps on the official application store of the most popular smartphone platform. In addition we expect users to have approximately 95 such applications installed on their smartphones at any given point. However, mobile apps are developed by untrusted sources. On Android—which enjoys 80% of the smartphone OS market share—application developers are identified based on self-sign certificates. Thus there is no good way of holding a developer accountable for a malicious behavior. This creates an issue of multi-tenancy on smartphones where principals from diverse untrusted sources share internal and external smartphone resources. Smartphone OSs rely on traditional operating system process isolation strategies to confine untrusted third-party applications. However this approach is insufficient because incidental seemingly harmless resources can be utilized by untrusted tenants as side-channels to bypass the process boundaries. Smartphones also introduced a permission model to allow their users to govern third-party application access to system resources (such as camera, microphone and location functionality). However, this permission model is both coarse-grained and does not distinguish whether a permission has been declared by a trusted or an untrusted principal. This allows malicious applications to perform privilege escalation attacks on the mobile platform. To make things worse, applications might include third- party libraries, for advertising or common recognition tasks. Such libraries share the process address space with their host apps and as such can inherit all the privileges the host app does. Identifying and mitigating these problems on smartphones is not a trivial process. Manual analysis on its own of all mobile apps is cumbersome and impractical, code analysis techniques suffer from scalability and coverage issues, ad-hoc approaches are impractical and susceptible to mistakes, while sometimes vulnerabilities are well hidden at the interplays between smartphone tenants and resources. In this work I follow an analytical approach to discover major security and privacy issues on smartphone platforms. I utilize the Android OS as a use case, because of its open-source nature but also its popularity. In particular I focus on the multi-tenancy characteristic of smartphones and identify the re- sources each tenant within a process, across processes and across devices can access. I design analytical tools to automate the discovery process, attacks to better understand the adversary models, and introduce design changes to the participating systems to enable robust fine-grained access control of resources. My approach revealed a new understanding of the threats introduced from third-party libraries within an application process; it revealed new capabilities of the mobile application adversary exploiting shared filesystem and permission resources; and shows how a mobile app adversary can exploit shared communication mediums to compromise the confidentiality of the data collected by external devices (e.g. fitness and medical accessories, NFC tags etc.). Moreover, I show how we can eradicate these problems following an architectural design approach to introduce backward-compatible, effective and efficient modifications in operating systems to achieve fine-grained application access to shared resources. My work has let to security changes in the official release of Android by Google.
  • Mechanistic insights into the direct synthesis of H2O2 on transition metal catalysts
    Scholarship
    Creator
    Wilson, Neil Marshall
    Description
    H2O2 is less environmentally impactful than many industrial oxidants such as Cl2. The auto-oxidation of anthraquinones is the current standard for industrial H2O2 production, however, this process requires significant energy input due to the extensive purification and concentration processes involved, making H2O2 cost-prohibitive for many oxidation processes. As a result, there is clear motivation for less expensive and energy-demanding chemistries for H2O2 production, such as the direct synthesis of H2O2 (H2 + O2 → H2O2), the most promising alternative to using anthraquinones. Unfortunately, the combustion of H2 is thermodynamically favored over direct synthesis to H2O2 on most transition metal catalysts, and so significant research has been directed towards improving catalyst selectivity towards H2O2 through various methods. Despite significant research, the mechanism of this reaction, and the reasons for the importance of seemingly unrelated factors (e.g., metal cluster size, solvent pH, alloying), have remained unclear. The aim of this work is to provide a fundamental understanding of these factors through rigorous experimental procedures and analysis. Here, we propose a mechanism for H2O2 formation on Pd clusters consistent with steady-state H2O2 and H2O formation rates measured as functions of reactant pressures and temperature, and the interpretations of proton concentration effects. H2O2 forms by sequential proton-electron transfer to O2 and OOH surface intermediates, whereas, H2O forms by O-O bond rupture within OOH surface species. Direct synthesis, therefore, does not proceed by the Langmuir-Hinshelwood mechanism often invoked. Rather, H2O2 forms by heterolytic reaction pathways resembling the two electron oxygen reduction reaction (ORR), however, the chemical potential of H2 replaces an external electrical potential as the thermodynamic driving force. Similar experimental procedures have shown that this proton-electron transfer mechanism is the same also on AuPd and PdZn catalysts. Among AuPd and PdZn catalysts, increases in the Au:Pd or Zn:Pd ratio leads to simultaneous but unequal increases in the activation enthalpies (∆H‡) for both H2O2 and H2O formation, which must result from significant electronic changes to Pd by Au or Zn. Detailed comparisons of these changes in ∆H‡ for H2O2 and H2O production to H2O2 selectivities provide compelling evidence that these electronic effects are primarily responsible for the high H2O2 selectivities commonly reported on bimetallic catalysts. Additionally, these results lack trends that suggest ensemble effects contribute significantly to the increase in H2O2 selectivity observed on bimetallic catalysts within the ranges of metal compositions tested here. AgPt octahedra with dilute concentrations of surface Pt atoms were synthesized to test for the presence of ensemble effects which presumably do not manifest until the active sites (i.e., Pt) are sufficiently diluted with a metal which weakly binds O2 (i.e., Ag). Combining Pt with Ag increases H2O2 selectivity and significantly modifies the electronic structure of Pt active sites, which is reflected by a red shift in the ν(C=O) singleton frequency in 13CO, which is accompanied by a significant decrease in ∆H‡ values for H2O2 formation and a smaller decrease for H2O formation. These combined results show that adding Ag to Pt increases H2O2 selectivity by a combination of electronic modification of Pt atoms (likely due to tensile strain effects) and a commensurate increase in the number of isolated Pt atoms that lack sufficiently large numbers of Pt atoms to cleave O-O bonds to form H2O. Collectively, the results of these studies clarify many previously reported phenomena and help to guide the rational design of selective catalysts for the direct synthesis of H2O2.
  • INHS Reports, Autumn 2009
    Scholarship
    Creator
    Illinois Natural History Survey
    Description
    Revisionary Synthesis of Deltocephaline Leafhoppers | Big Railroad Blues | How We COPE with Outreach and Education | Calendar Sales Items for October through December | Species Spotlight: Cooper's Hawk | The Naturalist's Apprentice: Hawk Crossword Puzzle
  • INHS Reports, Winter 2010
    Scholarship
    Creator
    Illinois Natural History Survey
    Description
    Interspecific Interactions between Invasive and Native Mosquitoes | Islands as Models for Biodiversity Studies | Can Riparian Forests Help Improve Stream communities in Illinois Agricultural Watersheds? | Ecosystem-scale Evaluation of Sound Bubble Barrier Technologies to Prevent Range Expansions of Asian Carps | Species Spotlight: Brown Recluse Spider | The Naturalist's Apprentice: Illinois Spiders
  • Facile Size-Controlled Synthesis of Fluorescent Carbon Nanoparticles with Size-Independent Optical Properties
    Scholarship
    Creator
    • Singh, Jasleena
    • Pan, Dipanjan
    • Schwartz-Duval, Aaron Star
    • Mistry, Neal
    • Golk, Kelsey
    • Srivastava, Indrajit
    Description
    Nanoparticle imaging probes and drug delivery systems have distinct advantages over free or diffusive delivery in that they can concentrate the imaging contrast agent and/or drug, elicit controlled release/degradation, and have a high surface area to volume ratio beneficial for attaching targeting ligands. The size of these nanoparticles affects delivery, retention, degradation rate, and sometimes the radiological properties of the particles. For many optically active nanoparticles (such as gold, silver, and quantum dots), the optical properties are directly dependent on the size and shape of the nanoparticles. While this provides a simplistic outlet for modifying the optical properties of those nanoparticles, it is limiting in that their applications are also dependent on morphology. In these works, we aim to determine if the optical properties of fluorescent carbon nanoparticles are dependent on size through variations in synthetic parameters. Fluorescent carbon nanoparticles with hydrodynamic diameters ranging from 10 – 500 nm were prepared through variations of sugar source, concentration of agave (as a sugar source) and incubation time. Through comparisons made between these nanoparticles, we found no change in the local absorbance maxima and refractive index, with < 5 nm shifting in fluorescence maxima location. We have observed that fluorescent carbon nanoparticles can be prepared within a large range of sizes (10 – 500 nm) without considerable shift in optical properties. Because of this observation, we can infer that the optical properties of fluorescent carbon nanoparticles are largely size independent.
  • The influence of early information on postsecondary affordability
    Scholarship
    Creator
    Hemenway, Bradley Keith
    Description
    Misconceptions on affordability remain a barrier to postsecondary access for millions of potential students. When students recognize financial aid availability during secondary school years, they gain the capability to better establish a curricular path that aligns with postsecondary aspirations. This dissertation assesses the use of residency-based financial aid programs and parents’ college assets as methods to generate early information on postsecondary affordability. Following a three-paper format, the first paper develops a typology organizing the growing number of residency-based “Promise” programs around the country. The typology captures variations in the geographic scope for eligibility, supplementary qualifications, funding sources, value, and redeeming criteria to generate a description and list of comparable programs. Identifying program comparability is a necessary step for research examining program outcomes. The first paper uses a cluster analysis methodology to identify programs comparable based on the advertised operational characteristics. I find three distinctly different groups of residency-based financial aid programs, which I term state-based aid programs, institutionally funded programs, and community-sustained programs. The typology is extended to identify the specific operational characteristics for which residency-based, community-sustained financial aid programs differ. The second paper uses a unique institutional-level dataset and quasi-experimental Difference-in-Difference design to examine changes in college readiness, postsecondary outcomes, and curriculum decisions resulting from the residency-based, community-sustained Dell and Evelyn Carroll Scholarship. The award guarantees all Meridian High School students last-dollar funding for unmet need at Richland Community College. I find that information about Carroll Scholarship eligibility increases the college-readiness levels among high-achieving high school graduates who elect to enroll at Richland. After enrollment, all Carroll-eligible students register for, and earn, a statistically significant increased number of credit hours. I also find evidence that the Carroll Scholarship impacts student’s curriculum selection. The final paper uses a quantitative, quasi-experimental design of the nationally representative Education Longitudinal Study of 2002. Propensity Score Matching models are used to estimate different parents’ college asset savings strategies impacts the likelihood of a child enrolling in postsecondary education after completing high school. I find an enrollment association from parent’s postsecondary savings across different socioeconomic and sociodemographic groups. The models evaluate student responsiveness differences based on socioeconomics, race, and ethnicity, and control for secondary school academic achievement and the amount saved.