3,825 research outputs found
The Hydrogeology and Water Supply Problems in North-Central Chile
The north-central zone of Chile is described with respect to groundwater
supply problems. In this region, groundwater is almost exclusively obtained
from the thin alluvium in the main transverse valleys, which descend from the
Andes in those sections where the valleys cross the northerly trending "central
valley." Because of the steep groundwater gradients prevailing, the groundwater
resources are closely related to seasonal recharge. As the area is arid to semiarid
and has been showing indications of increasing aridity over the past few years,
water supply problems are proving to be a serious development constraint.
Throughout the area, many examples of insufficient water supply may be encountered,
and the problems of water use management and the utilization for industrial
purposes of supplies such as seawater, brines, and sewage are now being considered
Evaluation of aerosolized medications during parabolic flight maneuvers
The goal was to visually evaluate the effect gravity has on delivery of medications by the use of various aerosol devices. During parabolic flight the same four aerosols were retested as performed in studio ground tests. It appears that the Cetacaine spray and the Ventolin inhaler function without failure during all test. The pump spray (Nostril) appeared to function normally when the container was full, however it appeared to begin to fail to deliver a full mist with larger droplet size when the container was nearly empty. The simple hand spray bottle appeared to work when the container was full and performed progressively worse as the container was emptied. During Apollo flights, it was reported that standard spray bottles did not work well, however, they did not indicate why. It appears that we would also conclude that standard spray bottles do not function as well in zero gravity by failing to produce a normal mist spray. The standard spray bottle allowed the fluid to come out in a narrow fluid stream when held with the nozzle either level or slightly tilted upward
Probabilities on Sentences in an Expressive Logic
Automated reasoning about uncertain knowledge has many applications. One
difficulty when developing such systems is the lack of a completely
satisfactory integration of logic and probability. We address this problem
directly. Expressive languages like higher-order logic are ideally suited for
representing and reasoning about structured knowledge. Uncertain knowledge can
be modeled by using graded probabilities rather than binary truth-values. The
main technical problem studied in this paper is the following: Given a set of
sentences, each having some probability of being true, what probability should
be ascribed to other (query) sentences? A natural wish-list, among others, is
that the probability distribution (i) is consistent with the knowledge base,
(ii) allows for a consistent inference procedure and in particular (iii)
reduces to deductive logic in the limit of probabilities being 0 and 1, (iv)
allows (Bayesian) inductive reasoning and (v) learning in the limit and in
particular (vi) allows confirmation of universally quantified
hypotheses/sentences. We translate this wish-list into technical requirements
for a prior probability and show that probabilities satisfying all our criteria
exist. We also give explicit constructions and several general
characterizations of probabilities that satisfy some or all of the criteria and
various (counter) examples. We also derive necessary and sufficient conditions
for extending beliefs about finitely many sentences to suitable probabilities
over all sentences, and in particular least dogmatic or least biased ones. We
conclude with a brief outlook on how the developed theory might be used and
approximated in autonomous reasoning agents. Our theory is a step towards a
globally consistent and empirically satisfactory unification of probability and
logic.Comment: 52 LaTeX pages, 64 definiton/theorems/etc, presented at conference
Progic 2011 in New Yor
ATLS-stowage and deployment testing of medical supplies and pharmaceuticals
The objective is to evaluate stowage and deployment methods for the Health Maintenance Facility (HMF) during microgravity. The specific objectives of this experiment are: (1) to evaluate the stowage and deployment mechanisms for the medical supplies; and (2) to evaluate the procedures for performing medical scenarios. To accomplish these objectives, the HMF test mini-racks will contain medical equipment mounted in the racks; and self-contained drawers with various mechanisms for stowing and deploying items. The medical supplies and pharmaceuticals will be destowed, handled, and restowed. The in-flight test procedures and other aspects of the KC-135 parabolic flight test to simulate weightlessness are presented
Health maintenance facility system effectiveness testing
The Medical Simulations Working Group conducted a series of medical simulations to evaluate the proposed Health Maintenance Facility (HMF) Preliminary Design Review (PDR) configuration. The goal of these simulations was to test the system effectiveness of the HMF PDR configurations. The objectives of the medical simulations are to (1) ensure fulfillment of requirements with this HMF design, (2) demonstrate the conformance of the system to human engineering design criteria, and (3) determine whether undesirable design or procedural features were introduced into the design. The simulations consisted of performing 6 different medical scenarios with the HMF mockup in the KRUG laboratory. The scenarios included representative medical procedures and used a broad spectrum of HMF equipment and supplies. Scripts were written and simulations performed by medical simulations working group members under observation from others. Data were collected by means of questionnaires, debriefings, and videotapes. Results were extracted and listed in the individual reports. Specific issues and recommendations from each simulation were compiled into the individual reports. General issues regarding the PDR design of the HMF are outlined in the summary report
Introducing SeamlessAccess.org: Delivering a Simpler, Privacy-Preserving Access Experience
Managing access to subscribed services in an era of abundance is a major challenge for libraries. Users have come to expect a seamless, personalized experience on their mobile devices, but traditional approaches to access management force librarians to choose between the anonymous ease of onsite IP authentication or the access friction experienced by users authenticating across multiple resources with Single Sign-On. Building on the work of the RA21 initiative, a recent NISO Recommended Practice on Improved Access to Institutionally Provided Information Resources charts a way forward. It will enable libraries to provide seamless, privacy-preserving and one-click access to its subscribed content from any device, any location, and from any starting point in the research process. The implementation of these recommendations will be led by SeamlessAccess.org, starting with a beta phase implementation in the fall of 2019. But how is user and data privacy protected? How is access simplified? How will numerous library use case scenarios be accommodated, and will current accessibility standards be implemented and supported? This paper discusses how these concerns are being addressed by a consortium of industry partners including librarians, access providers, publishers, and standards organizations. It also discusses how the coalition will manage this service for publishers and libraries while continuing to improve this user experience, provide governance on data policy and privacy issues, and maintain core web services specific to this initiative
Permian climate change recorded in palynomorph assemblages of Mozambique (Moatize Basin, eastern Tete Province)
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