Coe College
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Recent publications
While the interactions among glass formers and modifiers, e.g., connectivity and charge distribution, have been studied extensively in oxide glasses, the impact of a particular modifier species on the mechanical performance of aluminoborosilicate glasses is not well understood. This work compares the indentation properties of six aluminoborosilicate (ABS) glasses, each of which contains a different network modifier (NWM) with varying field strength (FS). Three alkali and three alkaline earth ABS glasses were designed with low NWM content and [NWM] ≈ [Al2O3], to test the modifier FS effect at low concentrations and to maximize three‐coordinated boron. It has been found that both hardness and crack resistance increase with increasing FS in these ABS systems, which is surprising in the context of historical reports. Using 11B, 27Al, and 29Si solid state NMR, this work provides evidence of how charge distributions differ as a function of NWM species, and how this relates to the observed indentation behaviors. This article is protected by copyright. All rights reserved
Apocalyptic thinking permeates Paul’s ideas about the gospel, God, the present age, and what is to come. Paul in his letters not only writes about the revelations that he himself has received (Gal 1:11–12, 2:2), but also how the gospel reveals God’s ultimate justice (Rom 1:17). Apocalypticism as an ideology is fundamentally concerned with justice and the expectation of a future intervention that will conclusively reconcile the injustices of the world with the justice of God. Though of course Paul never sat down and wrote an “Apocalypse” or even an apocalyptic letter, his letters reveal glimpses of the apocalyptic ways Paul thought about the world and humanity’s place in it. This article reviews the history and main tenets of apocalypticism and then examines three fundamental areas of apocalyptic thinking as expressed in Paul’s letters: the idea of apocalypse as full disclosure, the apocalyptic promise of full justice, and Paul’s use of apocalyptic ideas to reorient his readers to thinking about true-but-hidden identity, both of the “present evil age” (Gal 1:4) and of one’s current place in it. Paul draws upon and employs apocalyptic imagery to solve practical problems in his communities, equipping them to face the world with a full cosmic perspective.
The structure of liquid lithium pyroborate, Li4B2O5 (J = Li/B = 2), has been measured over a wide temperature range by high‐energy x‐ray diffraction, and compared to that of its glass and borate liquids of other compositions. The results indicate a gradual increase in tetrahedral boron fraction from 3(1)% to 6(1)% during cooling from T = 1271(15)K to 721(8)K, consistent with the larger N4 = 10(1)% found for the glass, and literature 11B NMR measurements. van't Hoff analysis based on a simple boron isomerization reaction BØ3O2– ⇌ BØO22– yields ΔH = 13(1)kJmol–1 and ΔS = 40(1)Jmol–1K–1 for the boron coordination change from 4 to 3, which are respectively smaller and larger than found for singly charged isomers for J≤1. With these we extend our model for N4(J,T), non‐bridging oxygen fraction fnbr(J,T), configurational heat capacity Cpconf(J,T) and entropy Sconf(J,T) contributions up to J = 3. A maximum is revealed in Cpconf(J,T = Tg) at J = 1, and shown semi‐quantitatively to lead to a corresponding maximum in fragility contribution, akin to that observed in the total fragilities by temperature‐modulated DSC. Lithium is bound to 4.6(2) oxygen in the pyroborate liquid, with 2.7(1) bonds centred around 1.946(8)Å and 1.9(1) around 2.42(1)Å. In the glass, nLiO = 5.4(4), the increase being due to an increase in the number of short Li–O bonds. This article is protected by copyright. All rights reserved
In this essay, we conduct a review of the ways in which Google Scholar, Scopus, and other bibliometric tools may prove useful for faculty in tenure and promotion decisions. We begin with an examination of literature from multiple disciplines on the use of bibliometric platforms. We then examine the metrics provided by these platforms for citation analysis and determine their relative strengths and weaknesses. We provide a quantitative descriptive analysis of the differences in metrics across 1,840 faculty in six disciplines across 40 institutions in eight different Carnegie Classifications. The work concludes with recommendations for supplementary metrics and a call for tenure and promotion committees to augment the additional metrics we present with other forms of colleague recognition of the scholarship tenure and promotion candidates.
A multi-spectroscopic investigation of glasses xPbO-(100-x)B2O3, where 30 ≤ x ≤ 80, was undertaken employing Raman, ²⁰⁷Pb static NMR, and ¹¹B MAS NMR spectroscopies. The Raman results were quantified and combined with quantitative NMR results to produce a coherent structural model. The fraction of four-coordinated borons (N4) has a maximum near x = 50, in contrast with alkali modified borates where the maximum is near x = 35–40. In the range x = 30–50, both NMR and Raman spectroscopies indicate that lead ion behaves more ionically. From x = 50–65, the spectroscopic results indicate a change in the lead-oxygen bonding character from ionic to covalent. At similar compositions, the borate network becomes more ionic while remaining under-modified compared to alkali borates; consistent with lead-oxygen bonding being important to the structural evolution. When x > 65, the lead-oxygen bonding becomes significantly covalent.
The size relevant non-linear optical (NLO) properties of potassium nitrate with tricine nanoparticles were studied. The potassium nitrate with tricine nanoparticles is prepared by the direct liquid injection chemical vapour deposition technique at different synthesis temperatures of 200 °C (PNT 200) and 300 °C (PNT 300). The basic properties such as morphology, functional groups, optical energy gap, magnetization, and non-linear optical properties of prepared nanoparticles were characterised by various techniques such as powder X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, UV-Vis spectroscopy, FTIR spectroscopy, DTA/TGA analysis, magnetization, and Z-scan experiments. The melting points of PNT 200 and PNT 300 samples were detected by the DTA analysis. The thermal stress during the sample synthesis process made the sample freely expand and contract with temperature changes. The optical, thermal, and magnetic behaviour changes caused by temperature gradients in PNT 200 and PNT 300 samples were demonstrated, and Z-scan studies revealed that these materials are suitable for NLO applications.
Cancer is a complex and uniquely personal disease. More than 1.7 million people in the United States are diagnosed with cancer every year. As the burden of cancer grows, so does the need for new, more effective therapeutics and for predictive tools to identify optimal, personalized treatment options for every patient. Cancer models that recapitulate various aspects of the disease are fundamental to making advances along the continuum of cancer treatment from benchside discoveries to bedside delivery. In this review, we use a thought experiment as a vehicle to arrive at four broad categories of cancer models and explore the strengths, weaknesses, opportunities, and threats for each category in advancing our understanding of the disease and improving treatment strategies.
Dwayne Moore (2021) argues that libertarians about free will who are reductive physicalists cannot make proper sense of free will. In doing so, he presents what he calls “the physical indeterminism luck objection” to libertarian free will. He goes on to consider three different contemporary naturalistic approaches to libertarian free will (LFW) – those of Christopher Franklin, Mark Balaguer, and Robert Kane – and argues that if understood as reductive physicalist views they all fall prey to this objection. While it’s not entirely clear that Kane is a reductive physicalist, it is clear that he would reject any kind of eliminative materialism or eliminative physicalism (Kane 1996, 147). Regardless, in this essay I argue that even if Kane’s view is a kind of reductive physicalist view, it is immune to the arguments made in Moore’s essay.
AISI O1 cold work steel is a hard-to-machine material as a reason of its good temperature resistance, superficial hardness, and lesser response to wear. Hence, material removal from such hard materials is both cost- and time-consuming. Conventional cutting fluids fail to lessen the hotness at the tool-work junction. This research work explores the effects of a uniquely prepared and eco-friendly cutting fluid on the cutting performance of AISI O1 steel using tool inserts of three different materials. The prepared cutting fluid, molybdenum disulfide nanoparticle (MoS2) blended in biodegradable vegetable oil (VO) was distributed into the cutting zone with the help of the minimum quantity lubricant (MQL) technique. The integrated approach of Taguchi’s average normalized S/N ratio-based RSM method was employed to model the parameters for better responses. The optimal condition predicted by the approach (the type of insert – CBN, Vc – 110.12 m/min, f – 0.08 mm/rev, and DOC – 0.20076 mm) was observed to produce noteworthy improvements in tool wear and lessen the cutting force in addition to a good surface finish. The study will offer the required guidance for tool and die industries handling AISI O1 steel and help researchers work towards sustainable machining.
Ophidiomyces ophidiicola is an emerging fungal pathogen associated with infections in snakes across North America. Although documented in Pennsylvania, O. ophidiicola has not been found at the Powdermill Nature Reserve (PNR) in southwestern Pennsylvania, where the snake assemblage has been studied since 2002 and several species have recently declined. We surveyed for O. ophidiicola and putative ophidiomycosis at PNR. We screened five species of free-ranging, wild snakes (n=34) for suspected ophidiomycosis by visually checking for dermatitis and swabbing for the presence of O. ophidiicola DNA. We found a moderate prevalence of snakes with skin lesions (n=15) but a low prevalence of snakes with O. ophidiicola DNA in traditional PCR assays (n=2). Both positive snakes belonged to the same species and only one presented with lesions. When quantitative PCR (qPCR) screens were performed on duplicate swabs, 19 snakes were positive for O. ophidiicola DNA, with positive individuals in two species. Mark-recapture methods revealed seasonal variability in disease dynamics for sampled snakes. One individual presented with less than five skin lesions and tested negative in May 2020, had more than five lesions with a high fungal DNA load in June 2020, and no lesions with a low fungal DNA load in July 2020. We also found that snakes sampled from under the same cover object at the same time either all tested positive or all negative, including one instance involving two species. Our results underscore the value of using multiple screening techniques for O. ophidiicola surveillance and repeated sampling of individuals to understand the dynamics of ophidiomycosis in wild populations as compared to single method and single timepoint approaches.
Structures of binary PbO‐SiO2 glasses have been studied in detail over the compositional range 35 to 80 mol% PbO using high‐resolution neutron diffraction, high‐energy x‐ray diffraction, static 207Pb NMR and structural modelling. The changes in the local environment of Pb(II) are subtle; it has a low coordination to oxygen (∼3 to 4) plus a stereochemically active electron lone‐pair and thus behaves as a glass network forming (or intermediate) cation over the entire composition range. This conclusion contradicts previous reports that Pb(II) is a network modifier at low concentrations, and is supported by an analysis of lead and alkaline earth silicate glass molar volumes. The Pb‐O peak bond length shortens by 0.04 Å with increasing PbO content, indicating stronger, more covalent bonding and consistent with an increase in the number of short (≤ 2.70 Å) Pb‐O bonds, from 3.3 to 3.6. This is accompanied by increased axial symmetry of the Pb(II) sites, and is interpreted as a gradual transition towards square pyramidal [PbO4] sites, such as those found in crystalline PbO polymorphs. An attendant decrease in the periodicity associated with the first sharp diffraction peak (FSDP) toward that of β‐PbO, accompanied by increases in the correlation lengths associated with the plumbite network (FSDP) and silicate anions (neutron pre‐peak), provides evidence of increased intermediate range order and has implications for the glass forming limit imposed by crystallisation. Pb(II) electron lone‐pairs occupy the natural voids within the silicate network at low PbO contents, whilst at high PbO contents they aggregate to create voids which form part of the plumbite network, analogous to the open channels in Pb11Si3O17 and the layered structures of α‐ and β‐PbO. Si‐O and Pb‐O bond lengths have been correlated with 29Si and 207Pb NMR chemical shifts respectively. This is the first time that such correlations have been demonstrated for glasses and attests to the accuracy with which pulsed neutron total scattering can measure average bond lengths. This article is protected by copyright. All rights reserved
Single crystals of semi-organic potassium hydrogen phthalate crystals and l-proline(LP) amino acid (0.5 mol%)-doped potassium hydrogen phthalate crystals were implanted with 10 keV Ar+ ions at various fluencies of 1 × 1015, 5 × 1015, 1 × 1016, and 5 × 1016 ions/cm2 to enhance their nonlinear optical property. Pure KHP, L-proline (0.5 mol%), and Ar+ ion-irradiated samples were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, UV–visible spectroscopy, photo luminescence spectroscopy, microhardness testing, dielectric study, and non-linear optical (NLO) behavior. The study reveals that the Ar+ ion irradiation led to physical and chemical changes which altered the mechanical and optical properties of the samples. The l-proline-doped KHP showed an improved second-harmonic generation (SHG) efficiency compared to the KHP Ar+ ion-irradiated crystals. The energy deposition by the ion beam in the sample was studied by simulations using SRIM-2013 program. The study reveals that the Ar+ ion irradiation indicated the role of defects which could have influenced the non-linear optical behavior. Theoretical values of SHG calculated using the Python computational package indicate that further increase of Ar+ ion fluence will increase the SHG in l-proline (0.5 mol%)-doped KHP crystal. Further, it was prognosticated that beyond the Ar+ ion fluence of 1.9 × 1017 ions/cm2, the crystal size diminished.
A 3-D dosimeter fills the need for treatment plan and delivery verification required by every modern radiation-therapy method used today. This report summarizes a proof-of-concept study to develop a water-equivalent solid 3-D dosimeter that is based on novel radiation-hard scintillating material. The active material of the prototype dosimeter is a blend of radiation-hard peroxide-cured polysiloxane plastic doped with scintillating agent P-Terphenyl and wavelength-shifter BisMSB. The prototype detector was tested with 6 MV and 10 MV X-ray beams at Ohio State University’s Comprehensive Cancer Center. A 3-D dose distribution was successfully reconstructed by a neural network specifically trained for this prototype. This report summarizes the material production procedure, the material’s water equivalency investigation, the design of the prototype dosimeter and its beam tests, as well as the details of the utilized machine learning approach and the reconstructed 3-D dose distributions.
X-ray diffraction with high-energy photons (synchrotron) and neutron diffraction are performed on binary vanadate glasses with MgO, Na2O, K2O to determine their structural units. The interpretation includes results of further binary vanadate glasses where vitreous V2O5 plays a key role. Different to the V2O5 crystal the structural model of the glass widely excludes three-fold coordinated oxygen according to Zachariasen’s rules of glass formation. Results from the literature of an extensive analysis of vanadate crystals are used. VO6 units exist in definite deformations. The corresponding out-of-center displacements of the V⁵⁺ ions are attributed to the second-order Jahn-Teller effects. The corresponding mechanisms are suggested to be effective also in glass structures. Two, three or four different V-O distances of this model are taken into account and allow a consistent modelling of the distributions of the bond lengths.
Due to the lower ionospheric thermal pressure and existence of the crustal magnetism at Mars, the Martian ionopause is expected to behave differently from the ionopause at Venus. We study the solar wind interaction and pressure balance at the ionopause of Mars using both in situ and remote sounding measurements from the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) instrument on the Mars Express orbiter. We show that the magnetic pressure usually dominates the thermal pressure to hold off the solar wind at the ionopause at Mars, with only 13% of the cases where the ionospheric thermal pressure plays a more important role in pressure balance. This percentage at Venus, however, is up to 65%. We also find that the ionopause altitude at Mars decreases as the normal component of the solar wind dynamic pressure increases, similar to the altitude variation of the ionopauses at Venus. Moreover, our results show that the ionopause thickness at Mars and Venus is mainly determined by the ion gyromotion and is equivalent to about 5 ion gyroradii.
Accurate state of charge (SOC) estimation of lithium-ion (Li-ion) batteries is crucial in prolonging cell lifespan and ensuring its safe operation for electric vehicle applications. In this article, we propose the deep learning-based transformer model trained with self-supervised learning (SSL) for end-to-end SOC estimation without the requirements of feature engineering or adaptive filtering. We demonstrate that with the SSL framework, the proposed deep learning transformer model achieves the lowest root-mean-square-error (RMSE) of 0.90% and a mean-absolute-error (MAE) of 0.44% at constant ambient temperature, and RMSE of 1.19% and a MAE of 0.7% at varying ambient temperature. With SSL, the proposed model can be trained with as few as 5 epochs using only 20% of the total training data and still achieves less than 1.9% RMSE on the test data. Finally, we also demonstrate that the learning weights during the SSL training can be transferred to a new Li-ion cell with different chemistry and still achieve on-par performance compared to the models trained from scratch on the new cell.
Predicting the liquid compositions that will vitrify at experimentally accessible quench rates remains one of the grand challenges in the field of condensed matter physics. This glass-forming ability can be quantified as the critical quench rate needed to suppress crystallization. Knowledge of this critical quench rate also informs which glass composition could be used for new applications. There have been several physical and empirical models presented in the literature to predict the critical quench rate/glass forming ability. These models range from those theoretically derived to those quantified only through experimental characterization. In this work, we instead propose a new method to calculate the critical quench rate using the recently developed toy landscape model combined with machine learning. The toy landscape model accesses the underlying physics that control the vitrification behavior by directly simulating the liquid thermodynamics and kinetics. The results are discussed in terms of industrial impact, physical insights, and how the glass science community can develop improved predictions of glass-forming ability.
No PDF available ABSTRACT To facilitate research into the acoustical properties of free reed instruments, there is a need for a quick and inexpensive way to prototype new geometries. It is here that a computational model with easily adjustable parameters offers a substantial advantage over an experimental apparatus if it can sufficiently resolve the essential acoustic features. Simulations using the finite element method have been utilized to solve the fluid dynamics, pressure acoustics, structural mechanics, and the multi-physics couplings underpinning various free reed systems. These phenomena include attack transients and frequency-pressure dependence of Western free reeds, fluid-structure interaction of turbulent airflow in an Asian free reed, effects of air compressibility on reed vibration, and the acoustic impedance of a reed-driven khaen pipe. Results consistent with experimental and analytical models were obtained and methods of optimizing the computational cost while maintaining realism are proposed. The models fail, however, to capture the essential feature of free reed sound production via the periodic interruption of airflow through the reed plate. Ways for future research to achieve this benchmark are suggested. [Research supported by National Science Foundation, Grant NSF-REU-1950337.]
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385 members
John Lemos
  • Philosophy and Religion
Stephen Hughes
  • Computer Science
Kimberly Rae Lanegran
  • Political Science
United States