906 research outputs found
Pedro Subiela: un alumno de Almadén en América
Con motivo de los actos conmemorativos del bicentenario de la Escuela de Minas, Antonio del Valle relató la influencia de los primeros ingenieros de Almadén en las minas americanas, resaltando la importancia del Despotismo Ilustrado y del Espíritu del Siglo. En dicho artículo anota la necesidad de sacar del anonimato a algunos alumnos de la Academia, tal es el caso de Pedro Subiela, componente de su primera promoción
Impact of uncertainty on modeling and testing
A thorough understanding of the uncertainties associated with the modeling and testing of the Space Shuttle Main Engine (SSME) Engine will greatly aid decisions concerning hardware performance and future development efforts. This report will describe the determination of the uncertainties in the modeling and testing of the Space Shuttle Main Engine test program at the Technology Test Bed facility at Marshall Space Flight Center. Section 2 will present a summary of the uncertainty analysis methodology used and discuss the specific applications to the TTB SSME test program. Section 3 will discuss the application of the uncertainty analysis to the test program and the results obtained. Section 4 presents the results of the analysis of the SSME modeling effort from an uncertainty analysis point of view. The appendices at the end of the report contain a significant amount of information relative to the analysis, including discussions of venturi flowmeter data reduction and uncertainty propagation, bias uncertainty documentations, technical papers published, the computer code generated to determine the venturi uncertainties, and the venturi data and results used in the analysis
Adam and Eve had a Wonderful Time
https://digitalcommons.library.umaine.edu/mmb-vp/1035/thumbnail.jp
Common structure in the heterogeneity of plant-matter decay
Carbon removed from the atmosphere by photosynthesis is released back by respiration. Although some organic carbon is degraded quickly, older carbon persists; consequently carbon stocks are much larger than predicted by initial decomposition rates. This disparity can be traced to a wide range of first-order decay-rate constants, but the rate distributions and the mechanisms that determine them are unknown. Here, we pose and solve an inverse problem to find the rate distributions corresponding to the decomposition of plant matter throughout North America. We find that rate distributions are lognormal, with a mean and variance that depend on climatic conditions and substrate. Changes in temperature and precipitation scale all rates similarly, whereas the initial substrate composition sets the time scale of faster rates. These findings probably result from the interplay of stochastic processes and biochemical kinetics, suggesting that the intrinsic variability of decomposers, substrate and environment results in a predictable distribution of rates. Within this framework, turnover times increase exponentially with the kinetic heterogeneity of rates, thereby providing a theoretical expression for the persistence of recalcitrant organic carbon in the natural environment
Potent Immunity to Low Doses of Influenza Vaccine by Probabilistic Guided Micro-Targeted Skin Delivery in a Mouse Model
Background: Over 14 million people die each year from infectious diseases despite extensive vaccine use [1]. The needle and syringe-first invented in 1853-is still the primary delivery device, injecting liquid vaccine into muscle. Vaccines could be far more effective if they were precisely delivered into the narrow layer just beneath the skin surface that contains a much higher density of potent antigen-presenting cells (APCs) essential to generate a protective immune response. We hypothesized that successful vaccination could be achieved this way with far lower antigen doses than required by the needle and syringe
The Vehicle, Fall 1996
Vol. 38, No. 1
Table of Contents
DarcyMichael Maypage 1
Time in TimeJoe Howardpage 2
Sestina for DyingAmy Haynespage 3
VioletsSandra Beauchamppage 5
Melody\u27s SongSandra Beauchamppage 7
A Spinning Top ContemplationThomas T. Brownpage 10
Lady of the NightShari Grierpage 13
The Difference Between a Hand and a Killing JarJason S. Loguepage 14
The Bat I KilledMichael Maypage 15
UntitledKimberly Mannypage 16
ReleaseKimberly Mannypage 17
Fountain in the RainEric Chisauskypage 18
War, the Old Fashioned WayCarmella Cosenzapage 19
AloneCarmella Cosenzapage 20
MotelMichael Maypage 21
UntitledAndrea Traxlerpage 22
UntitledMichael Maypage 23
From Across the CourtyardShannon Goodallpage 24
CommunionShannon Goodallpage 26
Please Come HomeKendall W. Baumannpage 27
UntitledMichael Maypage 29
Indefinite SacrificeAmanda Watsonpage 30
Recovery RoomAbby Kollerpage 31
Questioning FaithMichael Kawapage 31
MerulaMichael Maypage 32
Biographiespage 33https://thekeep.eiu.edu/vehicle/1066/thumbnail.jp
Desorption of hot molecules from photon irradiated interstellar ices
We present experimental measurements of photodesorption from ices of
astrophysical relevance. Layers of benzene and water ice were irradiated with a
laser tuned to an electronic transition in the benzene molecule. The
translational energy of desorbed molecules was measured by time-of-flight (ToF)
mass spectrometry. Three distinct photodesorption processes were identified - a
direct adsorbate-mediated desorption producing benzene molecules with a
translational temperature of around 1200 K, an indirect adsorbate-mediated
desorption resulting in water molecules with a translational temperature of
around 450 K, and a substrate-mediated desorption of both benzene and water
producing molecules with translational temperatures of around 530 K and 450 K
respectively. The translational temperature of each population of desorbed
molecules is well above the temperature of the ice matrix. The implications for
gas-phase chemistry in the interstellar medium are discussed.Comment: 23 pages, including 4 figures; submitted to Ap
Moderating Readers and Reading Online
Despite the proliferation of online forums for the discussion of literary texts, very little has been written to date on the management of these spaces and how this helps frame the kinds of discussion and interpretative work that take place. This article draws on a series of interviews with moderators of online book-related sites, alongside close analysis of online interactions between moderators and users to consider issues of authority, hierarchy, power and control, asking how these act to structure or facilitate acts of interpretation taking place online. We begin by outlining the moderator's role before conducting a brief review of existing scholarship on offline reading groups and online communities, to identify how social infrastructures are established and negotiated. The main body of the article draws upon interviews with moderators of two online literary forums – The Republic of Pemberley and The Guardian’s online Reading Group – to explore the ways in which each of the respective moderators frames his or her role. This is accompanied by an in-depth exploration of how the forms of interpretation we find on the two sites are shaped and directed by the moderators. The article concludes by reflecting upon some of the issues raised by this study and its methodology, particularly with regards to digital dualism and the blurring of the boundaries between the public and the private in online spaces
Towards Machine Wald
The past century has seen a steady increase in the need of estimating and
predicting complex systems and making (possibly critical) decisions with
limited information. Although computers have made possible the numerical
evaluation of sophisticated statistical models, these models are still designed
\emph{by humans} because there is currently no known recipe or algorithm for
dividing the design of a statistical model into a sequence of arithmetic
operations. Indeed enabling computers to \emph{think} as \emph{humans} have the
ability to do when faced with uncertainty is challenging in several major ways:
(1) Finding optimal statistical models remains to be formulated as a well posed
problem when information on the system of interest is incomplete and comes in
the form of a complex combination of sample data, partial knowledge of
constitutive relations and a limited description of the distribution of input
random variables. (2) The space of admissible scenarios along with the space of
relevant information, assumptions, and/or beliefs, tend to be infinite
dimensional, whereas calculus on a computer is necessarily discrete and finite.
With this purpose, this paper explores the foundations of a rigorous framework
for the scientific computation of optimal statistical estimators/models and
reviews their connections with Decision Theory, Machine Learning, Bayesian
Inference, Stochastic Optimization, Robust Optimization, Optimal Uncertainty
Quantification and Information Based Complexity.Comment: 37 page
Woodland Recovery after Suppression of Deer: Cascade effects for Small Mammals, Wood Mice (Apodemus sylvaticus) and Bank Voles (Myodes glareolus)
Over the past century, increases in both density and distribution of deer species in the Northern Hemisphere have resulted in major changes in ground flora and undergrowth vegetation of woodland habitats, and consequentially the animal communities that inhabit them. In this study, we tested whether recovery in the vegetative habitat of a woodland due to effective deer management (from a peak of 0.4–1.5 to <0.17 deer per ha) had translated to the small mammal community as an example of a higher order cascade effect. We compared deer-free exclosures with neighboring open woodland using capture-mark-recapture (CMR) methods to see if the significant difference in bank vole (Myodes glareolus) and wood mouse (Apodemus sylvaticus) numbers between these environments from 2001–2003 persisted in 2010. Using the multi-state Robust Design method in program MARK we found survival and abundance of both voles and mice to be equivalent between the open woodland and the experimental exclosures with no differences in various metrics of population structure (age structure, sex composition, reproductive activity) and individual fitness (weight), although the vole population showed variation both locally and temporally. This suggests that the vegetative habitat - having passed some threshold of complexity due to lowered deer density - has allowed recovery of the small mammal community, although patch dynamics associated with vegetation complexity still remain. We conclude that the response of small mammal communities to environmental disturbance such as intense browsing pressure can be rapidly reversed once the disturbing agent has been removed and the vegetative habitat is allowed to increase in density and complexity, although we encourage caution, as a source/sink dynamic may emerge between old growth patches and the recently disturbed habitat under harsh conditions
- …