82 research outputs found
Fluid quantity gaging
A system for measuring the mass of liquid in a tank on orbit with 1 percent accuracy was developed and demonstrated. An extensive tradeoff identified adiabatic compression as the only gaging technique that is independent of gravity or its orientation, and of the size and distribution of bubbles in the tank. This technique is applicable to all Earth-storable and cryogenic liquids of interest for Space Station use, except superfluid helium, and can be applied to tanks of any size, shape, or internal structure. Accuracy of 0.2 percent was demonstrated in the laboratory, and a detailed analytical model was developed and verified by testing. A flight system architecture is presented that allows meeting the needs of a broad range of space fluid systems without custom development for each user
SPECTROSCOPY OF THE LOW-ENERGY STATES OF BaO+
The BaO cation is a promising candidate for studies conducted at ultra-cold temperatures. It is known that the ion can be formed by the reaction of laser-cooled Ba with NO or O. Spectroscopic data are now needed for the BaO cation, for both characterization of the internal state population distributions and the design of population transfer schemes. We have obtained the first spectroscopic data for BaO using the pulsed-field ionization, zero kinetic energy (PFI-ZEKE) photoelectron technique. Two-color ionization was carried out via the A-X transition of BaO. Vibronic levels of the X, A and A states of BaO have been characterized. The results are compared with the predictions of high-level electronic structure calculations
SPECTROSCOPY OF THE LOW LYING STATES OF CaO+
Diatomic molecular ions that contain alkaline earth atoms are of interest for experiments involving ultra-cold molecular ions. The alkaline earth atomic cations are well suited for laser cooling as they have transitions that are analogous to those of the alkali metals. Hence, Coulomb crystals are readily formed in rf traps. Reactions of these atomic ions yield diatomic products that are sympathetically cooled to low translational temperatures by the surrounding atomic ions. In principle, spectroscopic measurements may be used to probe the internal energies of the molecular ions. However, gas phase spectroscopic data for the ions of interest are lacking. In the present study we have investigated CaO using pulsed field ionization-zero kinetic energy photoelectron spectroscopy (PFI-ZEKE). Molecular constants for low energy vibrational levels for the ground state () and two electronic states ( and ) have been determined. These measurements also provide the first accurate value for the ionization energy of CaO. Comparisons with high-level theoretical calculations will be discussed
TWO-PHOTON IONIZATION STUDY OF THE LOW LYING STATES OF UN+
The electronic structures of UN and UN are of interest for the testing and development of relativistic quantum chemistry methods. The ground state UN was probed by Matthew and Morse, who found that the electronic configuration (5f7s) differed from that of the isoelectronic UO cation (5f). In the present study we examine the ionization energy of UN and the low energy states of UN by means of pulsed-field ionization zero kinetic energy photoelectron spectroscopy (PFI-ZEKE). Resonantly enhanced two photon ionization (R2PI) coupled with a time of flight mass spectrometer was used to confirm production of the UN molecule and locate suitable electronically excited states for subsequent access to UN via high-n Rydberg states. The results will be compared to the predictions from ligand field theory and high-level ab ignition calculations.
1. D. J. Matthew and M. D. Morse, J. Chem. Phys. 138, 184303 (2013
The Development of a Point of Care Clinical Guidelines Mobile Application Following a User-Centred Design Approach
This paper describes the development of a point of care clinical guidelines mobile application. A user-centred design approach was utilised to inform the design of a smartphone application, this included: Observations; a survey; focus groups and an analysis of popular apps utilised by clinicians in a UK NHS Trust. Usability testing was conducted to inform iterations of the application, which presents clinicians with a variety of integrated tools to aid in decision making and information retrieval.
The study found that clinicians use a mixture of technology to retrieve information, which is often inefficient or has poor usability. It also shows that smartphone application development for use in UK hospitals needs to consider the variety of users and their clinical knowledge and work pattern. This study highlights the need for applying user-centred design methods in the design of information presented to clinicians and the need for clinical information delivery that is efficient and easy to use at the bedside
Design, development and validation of a model of problem solving for Egyptian Science classes
Educators and policymakers envision the future of education in Egypt as enabling learners to acquire scientific inquiry and problem-solving skills. In this article, we describe the validation of a model for problem solving and the design of instruments for evaluating new teaching methods in Egyptian science classes. The instruments were based on an established model for problem solving and were designed to assess seventh grade students’ problem solving, experimental strategy knowledge, achievement and motivation towards science. The test for assessing students’ knowledge has been developed based on the topic, density and buoyancy which will be taught in seventh grade in a later intervention study. The instruments were partly self-developed and partly adapted from newly performed studies on strategy knowledge and problem solving in Germany. All instruments were translated into Arabic; the translation process and quality control are described. In order to determine the quality of the instruments, 44 students in Egypt completed the questionnaires and tests. The study’s aim to develop and validate the instruments did require an ad hoc and typical sample which was drawn from an accessible population. Accordingly, the characteristics of the sample are described. Data were analysed according to the classical test theory, but to underpin the results, the instruments were additionally analysed using the even stronger Rasch model. The findings demonstrated the reliability of the items and aspects of validity. In addition, this study showed how test items can be successfully developed and adapted in an international study and applied in a different language
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