Quartz and Prehnite: Minerals during the Renaissance

Minerals were displayed in wonder rooms for their beauty and used by apothecaries for their medical properties and artists, for sculptures and pigments. Minerals during the Renaissance were collected and displayed in wonder rooms to illustrate the beauty of nature. Humanists would have categorized minerals by their external qualities- color, transparency, form, luster, and smell. Over time, geologists continue to study these external qualities when they are first analyzing minerals, and the internal properties. Today the six major factors in identifying minerals are cleavage, the tendency of minerals to break into flat surfaces; color; crystal form or how the form of the mineral changes as the mineral crystallizes; hardness, the resistance to scratching to measure its strength; luster, the light reflection; and streak, the color of the streak left when a mineral is grinded on porcelain. [excerpt

A Tradition of Bells: Glatfelter Bell and Hall

Every hour, students and staff hear the tolling of a bell. Some students hear it and count the number of times it rings to see what time it is. Others hear it and realize they are late to class. And many come back after they have graduated and are happy to hear the bell toll once more. There are many times when the bell is rung today. The bell is rung at graduation, funerals in the Chapel, and alumni and donor recognition. The Glatfelter Bell has been part of the Gettysburg experience since 1892. This bell is housed in one of the most iconic buildings on campus—Glatfelter Hall. The hall was built between 1887-1889, before the college considered buying the bell. Both Glatfelter and its bell have a long history that began with the building initiative of the late 1800’s beginning under the presidency of Dr. Milton Valentine and that came to fruition during the presidency of Harvey McKnight

Selective Lanthanide Sensing with Gold Nanoparticles and Hydroxypyridinone Chelators.

The octadentate hydroxypyridinone chelator 3,4,3-LI(1,2-HOPO) is a promising therapeutic agent because of its high affinity for f-block elements and noncytotoxicity at medical dosages. The interaction between 3,4,3-LI(1,2-HOPO) and other biomedically relevant metals such as gold, however, has not been explored. Gold nanoparticles functionalized with chelators have demonstrated great potential in theranostics, yet thus far, no protocol that combines 3,4,3-LI(1,2-HOPO) and colloidal gold has been developed. Here, we characterize the solution thermodynamic properties of the complexes formed between 3,4,3-LI(1,2-HOPO) and Au3+ ions and demonstrate how under specific pH conditions the chelator promotes the growth of gold nanoparticles, acting as both reducing and stabilizing agent. 3,4,3-LI(1,2-HOPO) ligands on the nanoparticle surface remain active and selective toward f-block elements, as evidenced by gold nanoparticle selective aggregation. Finally, a new colorimetric assay capable of reaching the detection levels necessary for the quantification of lanthanides in waste from industrial processes is developed based on the inhibition of particle growth by lanthanides

Patterned probes for high precision 4D-STEM bragg measurements.

Nanoscale strain mapping by four-dimensional scanning transmission electron microscopy (4D-STEM) relies on determining the precise locations of Bragg-scattered electrons in a sequence of diffraction patterns, a task which is complicated by dynamical scattering, inelastic scattering, and shot noise. These features hinder accurate automated computational detection and position measurement of the diffracted disks, limiting the precision of measurements of local deformation. Here, we investigate the use of patterned probes to improve the precision of strain mapping. We imprint a "bullseye" pattern onto the probe, by using a binary mask in the probe-forming aperture, to improve the robustness of the peak finding algorithm to intensity modulations inside the diffracted disks. We show that this imprinting leads to substantially improved strain-mapping precision at the expense of a slight decrease in spatial resolution. In experiments on an unstrained silicon reference sample, we observe an improvement in strain measurement precision from 2.7% of the reciprocal lattice vectors with standard probes to 0.3% using bullseye probes for a thin sample, and an improvement from 4.7% to 0.8% for a thick sample. We also use multislice simulations to explore how sample thickness and electron dose limit the attainable accuracy and precision for 4D-STEM strain measurements

Seniors and Information Technology: A MIS-Fit?

The “digital divide” between the haves and have-nots in society continues to draw attention in traditional media outlets as well as academic research. Those yearning to join the computer revolution comprise several groups defined by wealth, ethnicity, country (even regions of countries), and age. While there has been research into the digital divide in all of these areas, the focus of this paper is Information Technology (IT) use by the elderly, or our senior citizens. Our interest in this group stems from the dynamic interaction of two forces: 1) senior populations are growing in percentage and sheer number both in the United States and internationally; and 2) as a group, the elderly have more disposable income to spend on IT than their younger counterparts. In order to coordinate our research agenda, the current investigation presents a framework that delineates scholarly inquiry into this topic by the elements of the framework. We look at what has been done, and what we feel needs to be done, in order to incorporate an important demographic group into the mainstream of computing society: our seniors

py4DSTEM: a software package for multimodal analysis of four-dimensional scanning transmission electron microscopy datasets

Scanning transmission electron microscopy (STEM) allows for imaging, diffraction, and spectroscopy of materials on length scales ranging from microns to atoms. By using a high-speed, direct electron detector, it is now possible to record a full 2D image of the diffracted electron beam at each probe position, typically a 2D grid of probe positions. These 4D-STEM datasets are rich in information, including signatures of the local structure, orientation, deformation, electromagnetic fields and other sample-dependent properties. However, extracting this information requires complex analysis pipelines, from data wrangling to calibration to analysis to visualization, all while maintaining robustness against imaging distortions and artifacts. In this paper, we present py4DSTEM, an analysis toolkit for measuring material properties from 4D-STEM datasets, written in the Python language and released with an open source license. We describe the algorithmic steps for dataset calibration and various 4D-STEM property measurements in detail, and present results from several experimental datasets. We have also implemented a simple and universal file format appropriate for electron microscopy data in py4DSTEM, which uses the open source HDF5 standard. We hope this tool will benefit the research community, helps to move the developing standards for data and computational methods in electron microscopy, and invite the community to contribute to this ongoing, fully open-source project

John B. Bachelder’s Artistic Vision for the Gettysburg Battlefield

John Bachelder was an important artist and historian to Gettysburg, shaping the early interpretation of the battle during the Gettysburg Battlefield Memorial Association period (1863-1895). While he is mainly discussed as the first park historian, it is important to look at his career as an artist and how it influenced his career at Gettysburg. Looking at Bachelder’s entire career, one can see how Bachelder’s vision for the battlefield changed over time. Bachelder wanted to create a grand history painting of the battle, which ultimately became his Isometric Map of Gettysburg. He corresponded with veterans to get their accounts, leading Bachelder to learn more about the battlefield and to create his own interpretation of the battle. His early works, like the Isometric Map, the James Walker Repulse of Longstreet’s Assault, and guidebook (Gettysburg: What to See and How to See it) brought Gettysburg to the homes of Americans. This allowed Bachelder to become a more well-known name among veterans. Furthermore, these early works allowed Bachelder to begin his interpretation of Gettysburg. Ultimately, Bachelder saw Gettysburg as the most important battle of the Civil War, which culminated into the High-Water Mark of the Rebellion for the Confederate troops. This influences his later works, such as his history of the battle and his for the Gettysburg Battlefield Memorial Association as Superintendent of Monuments and Tablets. These later works focus on making Gettysburg a memorial landscape, and a battlefield park which visitors can understand by just looking at the field. Bachelder’s work is vital to understand the early interpretation of Gettysburg

The Use of an Expert System to Dynamically Alter Web Pages for One-to-One Marketing

One-to-one marketing on the Web is in its infancy. The Web offers a unique opportunity to mass market products directly to potential buyers who have a high probability for purchase, and to do so at a low cost. The key to unleashing this potential is the tailoring of Web presentation to address individual needs and desires quickly. This capability requires a mechanism for change so the site can adapt to the user. It also requires the ability to store and quickly access databases. We believe that an expert system is uniquely capable of providing this ability

A method for crystallographic mapping of an alpha-beta titanium alloy with nanometre resolution using scanning precession electron diffraction and open-source software libraries

An approach for the crystallographic mapping of two-phase alloys on the nanoscale using a combination of scanned precession electron diffraction and open source python libraries is introduced in this paper. This method is demonstrated using the example of a two-phase alpha / beta titanium alloy. The data was recorded using a direct electron detector to collect the patterns, and recently developed algorithms to then perform automated indexing and to analyse the crystallography from the results. Very high-quality mapping is achieved at a 3nm step size. The results show the expected Burgers orientation relationships between the alpha laths and beta matrix, as well as the expected misorientations between alpha laths. It is found that 180{\deg} ambiguities in indexing occur due to acquisition having been performed too close to a high symmetry zone axis of the beta with 2-fold projection symmetry (not present in 3D) in the Zero Order Laue Zone for some patterns and that this should be avoided in data acquisition in the future. Nevertheless, this study demonstrates a good workflow for the analysis of nanocrystalline two-phase or multiphase materials, which will be of widespread use in analysing two-phase titanium and other systems and how they evolve as a function of thermomechanical treatments.Comment: Submitted to Journal of Microscop

GSS Facilitation: Avoiding Intrusion in the Public Sector Task Domain

GSS is widely used and researched in the private sector; however, public sector GSS is lagging in both use and research. Public policy groups, legislative bodies, commissions and councils, etc., could all potentially benefit from GSS, yet their use of GSS is somewhere between infrequent and rare. Many of these groups might lack knowledge of GSS or access to the technology, but many of these groups might also be uncomfortable with the control that a facilitator has over the decision process. Before these groups can be comfortable with the prospect of improved decision-making through GSS, they need assurance that the facilitator will aid the decision process without biasing the outcomes of their deliberations. In this paper, we introduce three dimensions of facilitator intrusion and present a position that these intrusion effects warrant further research within the context of the public sector. Specifically, we posit that in public sector contexts, where fair and impartial processes are critical to the acceptance of decision outcomes, the potential for facilitator bias might be inhibiting the use of the technology