The Success Story of Gold-Based Catalysts for Gas- and Liquid-Phase Reactions: A Brief Perspective and Beyond

Gold has long held the fascination of mankind. For millennia it has found use in art, cosmetic metallurgy and architecture; this element is seen as the ultimate statement of prosperity and beauty. This myriad of uses is made possible by the characteristic inertness of bulk gold; allowing it to appear long lasting and above the tarnishing experienced by other metals, in part providing its status as the most noble meta

Systems analysis and optimization through discrete event simulation at Amazon.com

Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M. in Ocean Systems Management)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; in conjunction with the Leaders for Manufacturing Program at MIT, 2004.Includes bibliographical references (leaf 64).The basis for this thesis involved a six and a half month LFM internship at the Amazon.com fulfillment center in the United Kingdom. The fulfillment center management sought insight into the substantial variation across the entire fulfillment center. This variation manifested itself primarily in two areas: the individual process path productivities of picking, pre-sort, re-bin and packing, and the overall system productivities of fulfillment center cycle time and throughput. Employee productivities, within picking, pre-sort, re-bin and packing, varied substantially, with this variation having a significant effect on throughput. This thesis uses discrete event simulation and the program SIMUL8 to model the overall system and analyze the effect of this variation. It discusses the design and development process for the model, proposes key questions relative to variation, analyzes different scenarios, and recommends specific actions for implementation. The overall goals of the internship included increasing fulfillment center throughput and decreasing cycle time.by Cameron S. Price.S.M.in Ocean Systems ManagementM.B.A

Gordon Parks: “Homeward to the Prairie I Come” Digital Exhibition Catalog

This open access digital exhibition catalog is part of the Kansas State University (K-State) Gordon Parks Project, initiated by the Marianna Kistler Beach Museum of Art and K-State English. It presents new research about Parks’s activities in Kansas based on materials found in participating Kansas institutions, including 128 curated photographs donated by Gordon Parks to K-State. The contributions in this volume illuminate Parks’s relationship to his home state of Kansas as a source of reference and inspiration. They debunk the myth that Kansas was merely the place where Gordon Parks was born before moving on to greatness elsewhere. This book provides a series of intimate biographical snapshots of pivotal periods in the life of Gordon Parks. These short essays taken in their entirety, provide a dazzling and selected biography on the life of one of the most important photographers who lived and worked in the 20th and 21st century. These essays written by a range of writers and curators are engaging and are arranged thematically over the span of fifty years. The format of the book offers a new and unique method of connecting art, photography, film and biography. In reading this, the reader begins to imagine the life of a photographer who envisioned justice and attempted to realize it through his photographs and storytelling through his personal experiences. The power of his personal story is integrated with the personal, cultural, and politics of a time when he lived and worked in the field of photography addressing the challenges and triumphs of black people in America. This is a book that adds wonderfully to Gordon Parks life as it introduces new questions, specifically about sexual abuse in the Learning Tree and the “underdiscussed” activities of Parks life. --Deborah Willis, Ph.D. University Professor Chair, Department of Photography & Imaging New York University - Tisch School of the Arts Director, Center for Black Visual Culturehttps://newprairiepress.org/ebooks/1045/thumbnail.jp

Exploring the conditions required to form giant planets via gravitational instability in massive protoplanetary discs

We carry out global three-dimensional radiation hydrodynamical simulations of self-gravitating accretion discs to determine if, and under what conditions, a disc may fragment to form giant planets. We explore the parameter space (in terms of the disc opacity, temperature and size) and include the effect of stellar irradiation. We find that the disc opacity plays a vital role in determining whether a disc fragments. Specifically, opacities that are smaller than interstellar Rosseland mean values promote fragmentation (even at small radii, R < 25AU) since low opacities allow a disc to cool quickly. This may occur if a disc has a low metallicity or if grain growth has occurred. With specific reference to the HR 8799 planetary system, given its star is metal-poor, our results suggest that the formation of its imaged planetary system could potentially have occurred by gravitational instability. We also find that the presence of stellar irradiation generally acts to inhibit fragmentation (since the discs can only cool to the temperature defined by stellar irradiation). However, fragmentation may occur if the irradiation is sufficiently weak that it allows the disc to attain a low Toomre stability parameter.Comment: Accepted for publication by MNRAS. 11 pages, 12 figures

Patient-Centered Medical Homes in Community Oncology Practices: Changes in Spending and Care Quality Associated With the COME HOME Experience

PURPOSE: We examined whether the Community Oncology Medical Home (COME HOME) program, a medical home program implemented in seven community oncology practices, was associated with changes in spending and care quality. PATIENTS AND METHODS: We compared outcomes from elderly fee-for-service Medicare beneficiaries diagnosed between 2011 and 2015 with breast, lung, colorectal, thyroid, or pancreatic cancer, lymphoma, or melanoma and served by COME HOME practices before and after program implementation versus similar beneficiaries served by other geographically proximate oncologists. Difference-in-differences analysis compared changes in outcomes for COME HOME patients versus concurrent controls. Propensity score matching and regression methods were adjusted for clinical and sociodemographic differences. Our primary outcome was 6-month medical spending per beneficiary. Secondary outcomes included 6-month out-of-pocket spending, inpatient and ambulatory care–sensitive hospitalizations, readmissions, length of stay, and emergency department and evaluation and management visits. RESULTS: Before COME HOME, 6-month medical spending was $2,975 higher for the study group compared with controls (95$1,635 to $4,315; P \u3c .001) and increasing at a similar rate. After intervention, this difference was reduced to$318 (95% CI, −$1,105 to$1,741; P = .661), a significant change of −$2,657 (95$4,631 to −$683; P = .008) or 8.1$32,866). COME HOME was also associated with significantly reduced (10.2 %) emergency department visits per 1,000 patients per 6-month period (P = .024). There were no statistically significant differences in other outcomes. CONCLUSION: COME HOME was associated with reduced Medicare spending and improved emergency department use. The patient-centered medical home model holds promise for oncology practices, but improvements were not uniform

Physicochemical comparison of precipitated calcium carbonate for different configurations of a biogas upgrading unit

BACKGROUND: This paper presents a physicochemical comparison of the solid products obtained from two alternative processes that recycle waste sodium carbonate (Na2CO3) solution, which is produced following the absorption of CO2 in a biogas upgrading unit. Chemical regeneration processes offer an attractive alternative to the energetically demanding standard physical methods. In the first process, sodium hydroxide (NaOH) is regenerated as a precipitate from the chemical reaction of Na2CO3 with calcium hydroxide (Ca(OH)2). The second process shows a path to obtain a valuable sodium chloride (NaCl) and calcium carbonate (CaCO3) rich brine from calcium chloride (CaCl2) acting as a precipitant agent. In both processes, precipitated calcium carbonate (PCC) is obtained as the most valuable by‐product, but with varying properties owing to the different origin. RESULTS: The purpose of this work is to analyze physicochemically both variations of PCCs obtained and examine the differences between these solid samples in order to determine which method produces more desirable characteristics in the final product. To this end, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, X‐ray diffraction (XRD) and scanning electron microscopy (SEM) were employed as characterization methods. The results reflect that both PCCs have a calcite crystal structure, or morph, being as both PCC products originate from CaCl2 that is more similar to commercial calcium carbonate calcite. CONCLUSION: These results confirmed that a pure CaCO3 valuable by‐product can be obtained from a biogas upgrading unit with several industrial applications.This work was supported by the University of Seville through V PPIT-US. Financial support for this work was also provided by EPSRC grant EP/R512904/1 as well as Royal Society Research Grant RSGR1180353. This work was also partially sponsored by CO2ChemUK through EPSRC grant EP/P026435/1. Furthermore, this work was supported by EMASESA through the NURECCO2 project and Corporación Tecnológica de Andalucía (CTA)

The BATSE-Swift luminosity and redshift distributions of short-duration GRBs

We compare the luminosity function and rate inferred from the BATSE short hard bursts (SHBs) peak flux distribution with the redshift and luminosity distributions of SHBs observed by Swift/HETE II. While the Swift/HETE II SHB sample is incompatible with SHB population that follows the star formation rate, it is compatible with a SHB rate that reflect a distribution of delay times after the SFR. This would be the case if SHBs are associated with binary neutron star mergers. The available data allows, however, different interpretations. For example, a population whose rate is independent of the redshift fits the data very well. The implied SHB rates that we find range from $\sim 8$ to $\sim 30h_{70}^3$Gpc$^{-3}$yr$^{-1}$. This is a much higher rate than what was previously estimated. A detailed (2 dimensional) look at the best fit models shows, however, some discrepancy between the four Swift/HETE II SHBs and the models based on BATSE SHBs. This could be a statistical fluke. It could also arise from wrong estimates of the triggering criteria or from selection effects. If real it may indicate the existence of two SHB populations with different luminosity functions and redshift distributions.Comment: Revised version includes additional bursts and revised redshift of older burst

The new a-theory of time

The New A-theory of Time (TNAT) is the view, to be elaborated and defended in this article, that many times exist, and that time is real in virtue of every moment in time bearing each of the so-called A-properties: past, present and future. I argue that TNAT is at least as theoretically virtuous as mainstream views in the philosophy of time and may have some claim to being our best theory of time. I show that the properties ‘past’, ‘present’ and ‘future’ can be understood as compatible intrinsic properties. Having demonstrated that this account of the A-properties is coherent, I go on to demonstrate how TNAT can give us an account of passage, change and the truth-conditions for temporal sentences. In the final section of the article, I develop a tentative argument in favour of TNAT, though concede that we have to settle for the result that TNAT is on a par with our other theories of time. In the remainder of this opening section, my aim is to situate the current proposal as a direct response to McTaggart’s infamous argument against the reality of time

A supersonic crowdion in mica: Ultradiscrete kinks with energy between 40^{40}K recoil and transmission sputtering

In this chapter we analyze in detail the behaviour and properties of the kinks found in an one dimensional model for the close packed rows of potassium ions in mica muscovite. The model includes realistic potentials obtained from the physics of the problem, ion bombardment experiments and molecular dynamics fitted to experiments. These kinks are supersonic and have an unique velocity and energy. They are ultradiscrete involving the translation of an interstitial ion, which is the reason they are called 'crowdions'. Their energy is below the most probable source of energy, the decay of the $^{40}$K isotope and above the energy needed to eject an atom from the mineral, a phenomenon that has been observed experimentallyComment: 28 pages, 15 figure