Rescue litter flotation assembly Patent

Development and characteristics of rescue litter with inflatable flotation device for water rescue applicatio

A filter synthesis technique applied to the design of multistage broad-band microwave amplifiers

A method for designing multistage broad-band amplifiers based upon well-known filter synthesis techniques is presented. Common all-pole low-pass approximations are used to synthesize prototype amplifier circuits that may be scaled in frequency and impedance. All-pass filters introduced at the first stage are shown to improve input match while maintaining circuit performance less 6 dB gain. A theoretical comparison is made with the distributed amplifier and the cascaded single-stage distributed amplifier. Theoretically, a larger gain-bandwidth product is achieved using the synthesis technique. A proof-of-concept Butterworth low-pass two-stage amplifier was designed, simulated, and measured and achieved a flat gain performance of 1–4 GHz with a power gain of 14.5±1 dB close to the predicted 1–4.2 GHz, 15±1 dB

Space station experiment definition: Advanced power system test bed

A conceptual design for an advanced photovoltaic power system test bed was provided and the requirements for advanced photovoltaic power system experiments better defined. Results of this study will be used in the design efforts conducted in phase B and phase C/D of the space station program so that the test bed capabilities will be responsive to user needs. Critical PV and energy storage technologies were identified and inputs were received from the idustry (government and commercial, U.S. and international) which identified experimental requirements. These inputs were used to develop a number of different conceptual designs. Pros and cons of each were discussed and a strawman candidate identified. A preliminary evolutionary plan, which included necessary precursor activities, was established and cost estimates presented which would allow for a successful implementation to the space station in the 1994 time frame

Burgernomics: a big MacT guide to purchasing power parity

The theory of purchasing power parity (PPP) has long been a staple of international economic analysis. Recent years have seen the rise in popularity of a tongue-in-cheek, fast-food version of PPP: The Big Mac™ index. In this article, Michael Pakko and Patricia Pollard describe how comparisons of Big Mac prices around the world contain the ingredients necessary to demonstrate the fundamental principles of PPP. They show that the Big Mac index does nearly as well as more comprehensive measures of international price comparisons and that deviations from “McParity” illustrate why PPP often appears not to hold as a practical matter.Purchasing power parity

Change in viral bronchiolitis management in hospitals in the UK after the publication of NICE guideline.

BACKGROUND: Viral bronchiolitis is one of the most common causes of hospitalisation in young infants. It has previously been shown that many United Kingdom (UK) hospital Trusts were not compliant with many aspects of the National Institute for Health and Care Excellence (NICE) bronchiolitis guideline prior to its publication. OBJECTIVES: This study aimed to investigate changes in the management of bronchiolitis by hospital Trusts between 2015 (before NICE guideline publication) and 2017, after publication. STUDY DESIGN: We prospectively surveyed paediatricians at UK hospital Trusts on the management of bronchiolitis before (March to May 2015) and after (January to May 2017) the NICE bronchiolitis guideline publication in June 2015, using an electronic, structured questionnaire. RESULTS: In 2015 111 Trusts were represented and in 2017 100 Trusts. Significant improvements were seen in the use of nebulised bronchodilators and hypertonic saline and provision of parental written guidance. However, full compliance with the guideline did not change with 18% of Trusts compliant before publication of the guideline in 2015 and 19% fully compliant with the guideline in 2017. CONCLUSIONS: Overall there were modest but important improvements in the reported management of bronchiolitis after the publication of the NICE guideline

For here or to go? Purchasing power parity and the Big Mac

Purchasing power

Using think-aloud interviews to characterize model-based reasoning in electronics for a laboratory course assessment

Models of physical systems are used to explain and predict experimental results and observations. The Modeling Framework for Experimental Physics describes the process by which physicists revise their models to account for the newly acquired observations, or change their apparatus to better represent their models when they encounter discrepancies between actual and expected behavior of a system. While modeling is a nationally recognized learning outcome for undergraduate physics lab courses, no assessments of students' model-based reasoning exist for upper-division labs. As part of a larger effort to create two assessments of students' modeling abilities, we used the Modeling Framework to develop and code think-aloud problem-solving activities centered on investigating an inverting amplifier circuit. This study is the second phase of a multiphase assessment instrument development process. Here, we focus on characterizing the range of modeling pathways students employ while interpreting the output signal of a circuit functioning far outside its recommended operation range. We end by discussing four outcomes of this work: (1) Students engaged in all modeling subtasks, and they spent the most time making measurements, making comparisons, and enacting revisions; (2) Each subtask occurred in close temporal proximity to all over subtasks; (3) Sometimes, students propose causes that do not follow logically from observed discrepancies; (4) Similarly, students often rely on their experiential knowledge and enact revisions that do not follow logically from articulated proposed causes.Comment: 18 pages, 5 figure

The X-Ray Crystal Analyses of Some Organic and Charge-Transfer Compounds, and the Development of Related Computer Programs

The thesis is divided into three main parts; the first is devoted to a brief review of the theory and methods of X-ray Crystallography, the second describes a number of computer programs devised wholly or in part by the author, and the third presents four structural analyses. The computer programs found in Part II are written in KDF 9 - ALGOL, a subset of ALGOL 60. The ASS system of crystallographic computer programs is described and two programs from its structure solution aspect are reported. These are a Fourier-coefficient weighting program which weights a structure factor, for use in a Fourier summation, depending on the probability that its phase is correct, and a program which will provide a complete analysis of structure-factor data. Two other programs, more connected with structure refinement, are then discussed, an isotropic structure-factor least-squares program and a general anisotropic structure-factor program. Part III consists of the application of the X-ray method to organic structural problems. The crystal-structure analyses of the molecular complexes of anthracene and 1,12-dimethylbenzophenanthrene with 4-bromo-2,5,7-trinitrofluorenone are described and an account of the charge-transfer bonding Involved In the compounds is given. Two further structural analyses, those of a derivative of a degradation product of a pigment obtained from the bacterium Pseudomonas lemmonieri, and of the derivative of a tertiary alcohol, obtained from a reaction designed to yield a doubly bridged tricyclic molecule, are then presented and the results discussed