Oxidizer heat exchanger component testing

As part of the RL10 Rocket Engine Product Improvement Program, Oxidizer Heat Exchanger (OHE) stages 1, 2, and 3 were designed and fabricated during late 1983 and early 1984. The purpose of the OHE is to provide gaseous oxygen to the propellant injector for stable engine operation at tank head idle and pumped idle operating modes. This report summarizes the OHE stages 1 and 3 rig testing, and includes the separation of the stage 1-and-2 assembly and the remanifolding of stage 1. The OHE performance analysis and analytical model modifications for both stages are also presented. The flow tests were accomplished during the time period from 9 October 1984 to 12 November 1984

Tripropellant combustion process

The addition of small amounts of hydrogen to the combustion of LOX/hydrocarbon propellants in large rocket booster engines has the potential to enhance the system stability. Programs being conducted to evaluate the effects of hydrogen on the combustion of LOX/hydrocarbon propellants at supercritical pressures are described. Combustion instability has been a problem during the development of large hydrocarbon fueled rocket engines. At the higher combustion chamber pressures expected for the next generation of booster engines, the effect of unstable combustion could be even more destructive. The tripropellant engine cycle takes advantage of the superior cooling characteristics of hydrogen to cool the combustion chamber and a small amount of the hydrogen coolant can be used in the combustion process to enhance the system stability. Three aspects of work that will be accomplished to evaluate tripropellant combustion are described. The first is laboratory demonstration of the benefits through the evaluation of drop size, ignition delay and burning rate. The second is analytical modeling of the combustion process using the empirical relationship determined in the laboratory. The third is a subscale demonstration in which the system stability will be evaluated. The approach for each aspect is described and the analytical models that will be used are presented

In vitro generation of pancreatic β-cells for diabetes treatment. I. β-like cells derived from human pluripotent stem cells

Diabetes mellitus is a chronic disease that affects hundreds of millions of people worldwide. Type 1 diabetes (T1D) is characterized by the lack of pancreatic β-cells that had been destroyed as a result of an autoimmune response. Therefore, in patients with T1D, the replacement therapy with functional β-cells derived from extrinsic sources could be a preferable option as compared to insulin treatment. Unfortunately, successful transplantation of whole pancreata or pancreatic islets into patients with diabetes is available only to a fraction of them due to the scarcity of donors. The rapid development of cell reprogramming methods made it possible to generate large numbers of human β-like cells derived from human embryonic stem cells (hESCs) or human induced pluripotent stem cells (hiPSCs). This review describes the basis of in vitro differentiaton protocols of β-like cells that mimic changes of the main signaling pathways during the key stages of human and murine pancreas development, which are described first. During the last 15 years it was found that there are no important differences between hESCs and hiPSCs in their differentiation capacities into β-like cells and the expression profiles of the key transcription factors. The in vitro produced β-like cells are immature as demonstrated by functional tests in rodents and single-cell transcriptomic and proteomic analyses. After the transplantation of the β cell progenitors into immunocompromised diabetic mice, a few weeks have to pass before the increased insulin levels in response to glucose load appear. There is a continuous progress in the development of open-type encapsulation devices which allow the vascularization of the transplanted cells and protect them against host’s immune cells. The results of the first clinical trial of human partially differentiated endocrine progenitors of β cells transplanted into patients with T1D will be published in the year 2019. It is hoped that further improvements in the techniques of large-scale generation of the β-like cells derived from human pluripotent stem cells will bring us closer to their clinical application as a form of cause-directed therapy for people with diabetes.

Developing People's Information Capabilities: Fostering Information Literacy in Educational, Workplace and Community Contexts, Edited by Mark Hepworth and Geoff Walton

Developing People's Information Capabilities: Fostering Information Literacy in Educational, Workplace and Community Contexts is a fascinating read into the current research around the topic of information literacy

Crowdsourcing our Cultural Heritage, Edited by Mia Ridge

Crowdsourcing our Cultural Heritage provides a comprehensive view on the subject of working with our communities to increase our reach and enhance our collections. Though the book covers the entire GLAM sector (galleries, libraries, archives and museums), there’s much here to learn and consider for libraries who work in this space

Libraries and Public Perception: A Comparative Analysis of the European Press, By Anna Galluzzi

It’s not uncommon for libraries to prove their value to the communities they serve. Traditionally this comes through cost-benefit analyses or return-on-investment models. The problem with this sort of analysis is the focus on the quantitative and not the qualitative. ‘The price of everything, and the value of nothing,’ as Oscar Wilde might say

infinite states verification in game-theoretic logics

Many practical problems where the environment is not in the system's control such as service orchestration and contingent and multi-agent planning can be modelled in game-theoretic logics. This thesis demonstrates that the verification techniques based on regression and fixpoint approximation introduced in De Giacomo, Lesperance and Pearce [DLP10] do work on several game-theoretic problems. De Giacomo, Lesperance and Pearce [DLP10] emphasize that their study is essentially theoretical and call for complementing their work with experimental studies to understand whether these techniques are effective in practical cases. Several example problems with varying properties have been developed and, although not exhaustive nor complete,, our results nevertheless demonstrate that the techniques work on some problems. Our results show that the methods introduced in [DLP10] work for infinite domains where very few verification methods are available and allow reasoning about a wide range of game problems. Our examples also demonstrate the use of a rich language for specifying temporal properties proposed in [DLP10]. While classical model checking is well known and utilized, it is mostly restricted to finite-state models. A important aspect of the work is the demonstration of the use and effectiveness of characteristic graphs (ClaBen and Lakemeyer [CL08]) in verifying properties of games in infinite domains. A special-purpose programming language GameGolog proposed in De Giacomo, Lesperance and Pearce [DLP10] allows such game-theoretic systems to be specified procedurally at a high-level of abstraction. We show its practicality to model game structures in a convenient way that combines declarative and procedural elements. We provided examples to show the verification of GameGolog specifications using characteristic graphs. This thesis also proposes a refinement to the formalism in [DLP10] to incorporate action constraints as a mechanism to incorporate user strategies and for the modeller to supply heuristic guidance in temporal property verification. It also presents an implementation of evaluation-based fixpoint verifier that handles Situation Calculus game structures, as well as GameGolog specifications, for temporal property verification in the initial or a given situation. The verifier supports player action constraints